Nouns denoting substances

a colorless insoluble solid alcohol used to make detergents and pharmaceuticals
18-karat gold
an alloy that contains 75 per cent gold
2-hydroxybenzoic acid
a white crystalline substance with a bitter aftertaste; used as a fungicide or in making aspirin or dyes or perfumes
2-methylpropenoic acid
an unsaturated acid (C4H6O2) used to make resins and plastics
22-karat gold
an alloy that contains 87 per cent gold
24-karat gold
100 per cent gold
5-hydroxy-3-methylglutaryl-coenzyme A reductase
a liver enzyme that is responsible for producing cholesterol
a neurotransmitter involved in e.g. sleep and depression and memory
(biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
a dry form of lava resembling clinkers
ABO antibodies
blood type antibodies
a substance that abrades or wears down
any of a class of composite plastics used to make car bodies and cases for computers and other appliances
absinthe oil
a dark bitter oil obtained from wormwood leaves; flavors absinthe liqueurs
absolute alcohol
pure ethyl alcohol (containing no more than 1% water)
a material that has been or is capable of being absorbed
absorbent cotton
cotton made absorbent by removal of the natural wax
a material having capacity or tendency to absorb another substance
(physics) material in a nuclear reactor that absorbs radiation
absorption indicator
an indicator used in reactions that involve precipitation
a radioactive element of the actinide series; found in uranium ores
a chemical agent used to kill mites
acaroid resin
an alcohol-soluble resin from Australian trees; used in varnishes and in manufacturing paper
(chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected
(chemistry) in the formation of a coordinate bond it is the compound to which electrons are donated
acceptor RNA
RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell (according to directions coded in the mRNA)
proteolytic enzyme that converts angiotensin I into angiotensin II
any organic compound formed by adding alcohol molecules to aldehyde molecules
a colorless volatile water-soluble liquid aldehyde used chiefly in the manufacture of acetic acid and perfumes and drugs
unsaturated aldol
a colorless solid amide of acetic acid used as a solvent and in the synthesis of organic compounds
a salt or ester of acetic acid
acetic acid
a colorless pungent liquid widely used in manufacturing plastics and pharmaceuticals
acetic anhydride
a compound that is needed in order to refine opium into heroin
any of three liquid acetates that are formed when acetic acid and glycerin are heated together
acetoacetic acid
unstable acid found in abnormal amounts in the blood and urine in some cases of impaired metabolism (as diabetes mellitus or starvation)
acetone body
a ketone that is an intermediate product of the breakdown of fats in the body; any of three compounds (acetoacetic acid, acetone, and/or beta-hydroxybutyric acid) found in excess in blood and urine of persons with metabolic disorders
the simplest ketone; a highly flammable liquid widely used as an organic solvent and as material for making plastics
a dilute solution of acetic acid that is used as a solvent (e.g. for a drug)
acetyl chloride
colorless liquid acyl chloride (CH3COCl) that has a pungent odor
the organic group of acetic acid (CH3CO-)
a neurotransmitter that is a derivative of choline; released at the ends of nerve fibers in the somatic and parasympathetic nervous systems
a colorless flammable gas used chiefly in welding and in organic synthesis
any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt
acid anhydrides
organic compounds that react with water to form an acid
acid dye
dye in which the chromophore is part of a negative ion
acid halide
organic compounds containing the group -COX where X is a halogen atom
acid hydrogen
a hydrogen atom in an acid that forms a positive ion when the acid dissociates
acid-base indicator
an indicator that changes color on going from acidic to basic solutions
a pungent colorless unsaturated liquid aldehyde made from propene
a white crystalline amide of propenoic acid can damage the nervous system and is carcinogenic in laboratory animals
acrylate resin
a glassy thermoplastic; can be cast and molded or used in coatings and adhesives
a salt or ester of propenoic acid
acrylic acid
an unsaturated liquid carboxylic acid used in the manufacture of acrylic resins
polymerized from acrylonitrile
a colorless liquid unsaturated nitrile made from propene
one of the proteins into which actomyosin can be split; can exist in either a globular or a fibrous form
actinide series
(chemistry) a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium
any of a series of radioactive elements with atomic numbers 89 through 103
a green mineral of the amphibole group; calcium magnesium iron silicate
activated carbon
powdered or granular carbon used for purifying by adsorption; given orally (as a slurry) it is an antidote for some kinds of poisons
activating agent
(mineral extraction) a surface-active chemical used in flotation process to increase the attraction to a specific mineral
(biology) any agency bringing about activation; a molecule that increases the activity of an enzyme or a protein that increases the production of a gene product in DNA transcription
chemical agent capable of activity
a protein complex in muscle fibers; composed of myosin and actin; shortens when stimulated and causes muscle contractions
any group or radical of the form RCO- where R is an organic group
an ester of glycerol and fatty acids that occurs naturally as fats and fatty oils
an enzyme found in mammals that can catalyze the deamination of adenosine into inosine and ammonia
very hard native crystalline carbon valued as a gem
a compound formed by an addition reaction
(biochemistry) a nucleoside that is a structural component of nucleic acids; it is present in all living cells in a combined form as a constituent of DNA and RNA and ADP and ATP and AMP
ader wax
a waxy mineral that is a mixture of hydrocarbons and occurs in association with petroleum; some varieties are used in making ceresin and candles
dark greyish extrusive rock
a substance that unites or bonds surfaces together
adipic acid
a carboxylic acid used in the manufacture of nylon
Admiralty Metal
alpha-beta brass containing tin; resistant to sea water; Admiralty Metal is a trademark
the clay from which adobe bricks are made
an ester of adenosine that is converted to ATP for energy storage
adrenal cortical steroid
a steroid hormone produced by the adrenal cortex or synthesized; administered as drugs they reduce swelling and decrease the body's immune response
a steroid having androgenic activity; obtained from the cortex of the adrenal gland
a material that has been or is capable of being adsorbed
a material having capacity or tendency to adsorb another substance
any substance that lessens the purity or effectiveness of a substance
a potent carcinogen from the fungus Aspergillus; can be produced and stored for use as a bioweapon
an abnormally large amount of this fetoprotein in the fetus can signal an abnormality of the neural tube (as spina bifida or anencephaly)
a toxic mixture of gases (including carbon dioxide and carbon monoxide and nitrogen) after an explosion of firedamp in a mine
a soft white precious univalent metallic element having the highest electrical and thermal conductivity of any metal; occurs in argentite and in free form; used in coins and jewelry and tableware and photography
a colloidal extract of algae; used especially in culture media and as a gelling agent in foods
any culture medium that uses agar as the gelling agent
an impure form of quartz consisting of banded chalcedony; used as a gemstone and for making mortars and pestles
a yellow pungent volatile oil (trade name Agene) formerly used for bleaching and aging flour
a substance that exerts some force or effect
Agent Orange
a herbicide used in the Vietnam War to defoliate forest areas
volcanic rock consisting of large fragments fused together
an antibody that causes agglutination of a specific antigen
any substance that acts as an antigen to cause agglutinin production
material such as sand or gravel used with cement and water to make concrete, mortar, or plaster
a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of
once thought to be one of four elements composing the universe (Empedocles)
air cushion
the trapped air that supports a hovercraft a short distance above the water or ground
air gas
a gas made of carbon monoxide and hydrogen and nitrogen; made by passing air over hot coke
a silvery ductile metallic element found primarily in bauxite
a compact fine-textured, usually white gypsum used for carving
a crystalline amino acid that occurs in many proteins
a chemical sprayed on fruit trees to regulate their growth so the entire crop can be harvested at one time
a widely distributed feldspar that forms rocks
a simple water-soluble protein found in many animal tissues and liquids
a simple protein found in horny and cartilaginous tissues and in the lens of the eye
hypothetical universal solvent once sought by alchemists
an acid formed as an intermediate product of the metabolism of tyrosine and phenylalanine
any of a series of volatile hydroxyl compounds that are made from hydrocarbons by distillation
alcohol group
the chemical group -OH
a synthetic corticosteroid (trade name Aldactone) used to treat hypertension
any of a class of highly reactive chemical compounds; used in making resins and dyes and organic acids
aldehyde group
the chemical group -CHO
an oily colorless liquid obtained by the condensation of two molecules of acetaldehyde; contains an alcohol group (-OH) and an aldehyde group (-CHO)
a monosaccharide sugar having six carbon atoms and an aldehyde group
a monosaccharide sugar that contains the aldehyde group or is hemiacetal
a corticosteroid hormone that is secreted by the cortex of the adrenal gland; regulates salt (sodium and potassium) and water balance
granular protein in outermost layer of endosperm of many seeds or cereal grains
a green variety of chrysoberyl used as a gemstone
a gum used especially as a thickener or emulsifier
alicyclic compound
an aliphatic compound that contains a ring of atoms
aliphatic compound
organic compound that is an alkane or alkene or alkyne or their derivative
alizarin carmine
any of various acid dyes; used for dyeing wool scarlet red
alizarin yellow
any of various yellow dyes; not related chemically to alizarin but applied in the same manner
an orange-red crystalline compound used in making red pigments and in dyeing
a commercial antacid that contains aspirin; tablets dissolve in water to give an effervescent solution
a mixture of soluble salts found in arid soils and some bodies of water; detrimental to agriculture
alkali metal
any of the monovalent metals of group I of the periodic table (lithium or sodium or potassium or rubidium or cesium or francium)
any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water
alkaline earth
any of the bivalent metals of group II of the periodic table (calcium or strontium or barium or magnesium or beryllium)
an agent that counteracts or neutralizes acidity (especially in the stomach)
natural bases containing nitrogen found in plants
a series of non-aromatic saturated hydrocarbons with the general formula CnH(2n+2)
any unsaturated aliphatic hydrocarbon
a durable synthetic resin widely used in adhesives and paints
alkyl halide
organic compound in which halogen atoms have been substituted for hydrogen atoms in an alkane
any of a series of univalent groups of the general formula CnH2n+1 derived from aliphatic hydrocarbons
organic compound that has an alkyl group bound to a benzene ring
sulfonate of alkyl benzene
any substance that can cause an allergy
leather made from alligator's hide
an antibody that occurs naturally against foreign tissues from a person of the same species
any of several different crystalline forms of the same chemical compound
a structurally different form of an element
alloy cast iron
cast iron containing alloying elements (usually nickel or chromium or copper or molybdenum) to increase the strength or facilitate heat treatment
alloy steel
steel who characteristics are determined by the addition of other elements in addition to carbon
a mixture containing two or more metallic elements or metallic and nonmetallic elements usually fused together or dissolving into each other when molten
alluvial soil
a fine-grained fertile soil deposited by water flowing over flood plains or in river beds
allyl alcohol
an unsaturated primary alcohol present in wood spirit; use to make resins and plasticizers and pharmaceuticals
allyl resin
a resin derived from allyl alcohol that hardens when cured; used as an adhesive
the univalent unsaturated organic radical C3H5; derived from propylene
a purple variety of the ruby spinel
a deep red garnet consisting of iron aluminum silicate
trade name for an alloy used to make high-energy permanent magnets; contains aluminum and iron and nickel plus cobalt or copper or titanium
wool of the alpaca
alpha brass
an alloy of brass and zinc; used mainly for cold working
alpha bronze
an alloy of copper and tin that can be worked
alpha globulin
a globulin in blood plasma or serum that is alkaline and has great electrophoretic mobility
alpha iron
a magnetic allotrope of iron; stable below 906 degrees centigrade
alpha-linolenic acid
a polyunsaturated fatty acid with 18 carbon atoms; the only omega-3 fatty acid found in vegetable products; it is most abundant in canola oil; a fatty acid essential for nutrition
an isomer of naphthol used in dyes
a potent form of vitamin E obtained from germ oils or by synthesis
a white crystalline double sulfate of aluminum: the ammonium double sulfate of aluminum
a white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum
any of various forms of aluminum oxide occurring naturally as corundum
a compound of alumina and a metallic oxide
aluminium bronze
an alloy of copper and aluminum with high tensile strength and resistance to corrosion
aluminium chloride
a chloride used as a wood preservative or catalyst
aluminium hydroxide
white crystalline compound that occurs naturally as the mineral gibbsite
a substance made of fused alumina
a radioactive transuranic metallic element; discovered by bombarding uranium with helium atoms
an alloy of mercury with another metal (usually silver) used by dentists to fill cavities in teeth; except for iron and platinum all metals dissolve in mercury and chemists refer to the resulting mercury mixtures as amalgams
a hard yellowish to brownish translucent fossil resin; used for jewelry
waxy substance secreted by the sperm whale and found floating at sea or washed ashore; used in perfume
a white or grey mineral consisting of lithium aluminum phosphate; a source of lithium
a mixture of nectar and pollen prepared by worker bees and fed to larvae
a transparent purple variety of quartz; used as a gemstone
any organic compound containing the group -CONH2
a compound derived from ammonia by replacing hydrogen atoms by univalent hydrocarbon radicals
amino acid
organic compounds containing an amino group and a carboxylic acid group
amino plastic
a plastic (synthetic resin) made from amino compounds; used as an adhesive and as a coating for paper and textiles
the radical -NH2
oily poisonous liquid amine obtained from nitrobenzene and used to make dyes and plastics and medicines
aminobenzoic acid
a derivative of benzoic acid
a methyl with the hydrogen atom replaced by an amino radical
a class of transferases that catalyze transamination (that transfer an amino group from an amino acid to another compound)
a complex inorganic compound that contains ammonia molecules
a pungent gas compounded of nitrogen and hydrogen (NH3)
a water solution of ammonia
the aromatic gum of the ammoniac plant
ammonium carbamate
a salt of carbamic acid that is used as a nitrogen fertilizer
ammonium carbonate
a carbonate of ammonium; used in the manufacture of smelling salts and baking powder and ammonium compounds
ammonium chloride
a white salt used in dry cells
ammonium nitrate
used as an explosive and fertilizer and rocket propellant
the ion NH4 derived from ammonia; behaves in many respects like an alkali metal ion
any nuclear or chemical or biological material that can be used as a weapon of mass destruction
a nucleotide found in muscle cells and important in metabolism; reversibly convertible to ADP and ATP
a mineral or mineral variety belonging to the amphibole group
amphibole group
a group of minerals with similar crystal structures containing a silicate chain and combinations of chiefly sodium and calcium and magnesium and iron and aluminum
a metamorphic rock composed chiefly of amphibole and plagioclase
a bitter cyanogenic glucoside extracted from the seeds of apricots and plums and bitter almonds
volcanic rock in which rounded cavities formed by expanding gas have subsequently become filled with mineral deposits
a hydrocarbon radical that occurs in many organic compounds
amyl alcohol
a mixture of 2 or more isomeric alcohols; used as a solvent and in organic synthesis
any of a group of proteins found in saliva and pancreatic juice and parts of plants; help convert starch to sugar
(pathology) a waxy translucent complex protein resembling starch that results from degeneration of tissue
a non-nitrogenous food substance consisting chiefly of starch; any substance resembling starch
a complex carbohydrate found chiefly in seeds, fruits, tubers, roots and stem pith of plants, notably in corn, potatoes, wheat, and rice; an important foodstuff and used otherwise especially in adhesives and as fillers and stiffeners for paper and textiles
anabolic steroid
any of a group of synthetic steroid hormones used to stimulate muscle and bone growth; more than 100 have been developed and each requires a prescription to be used legally in the United States; sometimes used illicitly by athletes to increase their strength
a bacterial toxin that has been weakened until it is no longer toxic but is strong enough to induce the formation of antibodies and immunity to the specific disease caused by the toxin
a dark grey volcanic rock
a garnet consisting of calcium iron silicate and having any color ranging from yellow and green to brown and black; used as gemstone
male sex hormone that is produced in the testes and responsible for typical male sexual characteristics
an androgenic hormone that is less active than testosterone
a compound formed from one or more other compounds in a reaction resulting in removal of water
a blue dye obtained from plants or made synthetically
aniline dye
any of many dyes made from aniline
animal black
black substance containing char in the form of carbonized bone; used as a black pigment
animal fat
any fat obtained from animals
animal fiber
fiber derived from animals
animal glue
a protein gelatin obtained by boiling e.g. skins and hoofs of cattle and horses
animal material
material derived from animals
animal oil
any oil obtained from animal substances
animal pigment
pigment occurring in animals
animal product
a product made from animal material
animal skin
the outer covering of an animal
animal starch
one form in which body fuel is stored; stored primarily in the liver and broken down into glucose when needed by the body
animal toxin
a toxin resembling bacterial toxins in its antigenic properties that is found in the fluids of certain animals
any of various resins or oleoresins
anionic compound
a compound characterized by an active anion
a class of synthetic detergents in which the molecules do not ionize in aqueous solutions
rare plagioclastic feldspar occurring in many igneous rocks
a dark brown mineral of the amphibole group; magnesium iron silicate
a hard natural coal that burns slowly and gives intense heat
any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response
(chemistry) a substance that retards a chemical reaction or diminishes the activity of a catalyst
a liquid added to the water in a cooling system to lower its freezing point
any substance (as a toxin or enzyme) that stimulates an immune response in the body (especially the production of antibodies)
antigenic determinant
the site on the surface of an antigen molecule to which an antibody attaches itself
any of various compounds that are added to gasoline to reduce engine knocking
matter consisting of elementary particles that are the antiparticles of those making up normal substances
antimonial lead
a lead alloy that contains about 5% antimony
antimony potassium tartrate
a poisonous colorless salt used as a mordant and in medicine
substance that inhibits oxidation or inhibits reactions promoted by oxygen or peroxides
an antibody that can neutralize a specific toxin
an antitoxin that counteracts the effects of venom from the bite of a snake or insect or other animal
a common complex mineral consisting of calcium fluoride phosphate or calcium chloride phosphate; a source of phosphorus
fine-grained homogeneous rock (such as basalt) containing minerals undetectable by the naked eye
light-colored and fine-grained granitic rock consisting chiefly of quartz and feldspars
a protein that combines with a coenzyme to form an active enzyme
aqua fortis
acid used especially in the production of fertilizers and explosives and rocket fuels
aqua regia
a yellow fuming corrosive mixture of nitric and hydrochloric acid that dissolves metals (including gold)
a transparent variety of beryl that is blue green in color
aqueous solution
a solution in water
a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere
a mineral form of crystalline calcium carbonate; dimorphic with calcite
a purplish dye obtained from orchil lichens
arenaceous rock
a sedimentary rock composed of sand
a metal tincture used in heraldry to give a silvery appearance
a valuable silver ore consisting of silver sulfide (Ag2S)
a white clay (especially a white clay used by potters)
argillaceous rock
a sedimentary rock formed from clay deposits
a sedimentary rock differing from shale in being bound by silica and from slate in having no slate cleavages
a bitter tasting amino acid found in proteins and necessary for nutrition; its absence from the diet leads to a reduced production of spermatozoa
any of the chemically inert gaseous elements of the helium group in the periodic table
a rare steel-grey mineral consisting of silver and germanium and sulfur
a synthetic corticosteroid (trade names Aristocort or Aristopak or Kenalog) used as an anti-inflammatory agent
aromatic compound
a hydrocarbon containing one or more benzene rings that are characteristic of the benzene series of compounds
aromatic hydrocarbon
a hydrocarbon that contains one or more benzene rings that are characteristic of the benzene series of organic compounds
a nutritive starch obtained from the root of the arrowroot plant
a salt or ester of arsenic acid
arsenic acid
an acid formed from arsenic pentoxide
arsenic group
the univalent group derived from arsine
a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer
a pesticide or drug containing arsenic
a compound of arsenic with a more positive element
a silver-white or grey ore of arsenic
a poisonous colorless flammable gas used in organic synthesis and to dope transistors and as a poison gas in warfare
art paper
a high-quality paper (usually having a filler of china clay)
artificial blood
a liquid that can carry large amounts of oxygen and can serve as a temporary substitute for blood
a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and realgar
asa dulcis
gum resin used especially in treating skin irritation
the brownish gum resin of various plants; has strong taste and odor; formerly used as an antispasmodic
a fibrous amphibole; used for making fireproof articles; inhaling fibers can cause asbestosis or lung cancer
the residue that remains when something is burned
a crystalline amino acid found in proteins and in many plants (e.g., asparagus)
aspartic acid
a crystalline amino acid found in proteins and occurring naturally in sugar beets and sugar cane
mixed asphalt and crushed gravel or sand; used especially for paving but also for roofing
a dark bituminous substance found in natural beds and as residue from petroleum distillation; consists mainly of hydrocarbons
a substance that is undergoing an analysis of its components
the fur of young lambs
a highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium
essential oil or perfume obtained from flowers
(physics and chemistry) the smallest component of an element having the chemical properties of the element
(nontechnical usage) a tiny piece of anything
a nucleotide derived from adenosine that occurs in muscle tissue; the major source of energy for cellular reactions
a synthetic compound derived from triazine that is widely used as an agricultural herbicide
attar of roses
a volatile fragrant oil obtained from fresh roses by steam distillation
a soft yellow malleable ductile (trivalent and univalent) metallic element; occurs mainly as nuggets in rocks and alluvial deposits; does not react with most chemicals but is attacked by chlorine and aqua regia
dark-green to black glassy mineral of the pyroxene group containing large amounts of aluminum and iron and magnesium
a solid solution of ferric carbide or carbon in iron; cools to form pearlite or martensite
austenitic manganese steel
a steel with a relatively large component (10-14%) of manganese; highly resistant to wear and shock
austenitic steel
steel that has enough nickel and chromium or manganese to retain austenite at atmospheric temperatures
an antibody acting against tissues of the organism that produces it
a plant hormone that promotes root formation and bud growth
a translucent quartz spangled with bits of mica or other minerals
axle grease
a thick heavy grease used to lubricate axles
a chemical compound containing the azido group combined with an element or radical
azido group
the univalent group N3- derived from hydrazoic acid
azo dye
any dye containing one or more azo groups
azo group
the bivalent group -N=N- united to two hydrocarbon groups
an obsolete name for nitrogen
blue carbonate of copper; blue malachite
a trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder
B-complex vitamin
originally thought to be a single vitamin but now separated into several B vitamins
a soft silvery metallic element of the alkali earth group; found in barite
Babbitt metal
an alloy of tin with some copper and antimony; a lining for bearings that reduces friction
the large log at the back of a hearth fire
any chemical agent that destroys bacteria
bacterial toxin
any endotoxin or exotoxin formed in or elaborated by bacterial cells
a chemical or biological material that inhibits bacterial growth
a mineral consisting of zirconium oxide
the dry dusty pulp that remains after juice is extracted from sugar cane or similar plants
a thermosetting plastic used as electric insulators and for making plastic ware and telephone receivers etc.
baking powder
any of various powdered mixtures used in baking as a substitute for yeast
baking soda
a white soluble compound (NaHCO3) used in effervescent drinks and in baking powders and as an antacid
a pale rose-colored variety of the ruby spinel
a horny material from the upper jaws of certain whales; used as the ribs of fans or as stays in corsets
coarse gravel laid to form a bed for streets and railroads
an explosive (trade name Ballistite) that burns with relatively little smoke; contains pyrocellulose and is used as a propellant
any of various aromatic resinous substances used for healing and soothing
balm of Gilead
a fragrant oleoresin
any of various fragrant oleoresins used in medicines and perfumes
balsam capivi
an oleoresin used in varnishes and ointments
banana oil
a liquid ester derived from amyl alcohol; has the odor of bananas
bank gravel
gravel as found in natural deposits
barbituric acid
a white crystalline acid derived from pyrimidine; used in preparing barbiturate drugs
the matter ejected in vomiting
a white or colorless mineral (BaSO4); the main source of barium
barium dioxide
a white toxic powder obtained by heating barium oxide in air
barium hydroxide
white poisonous crystals; made by dissolving barium oxide in water
barium monoxide
an oxide of barium; a whitish toxic powder
barium sulfate
a white insoluble radiopaque powder used as a pigment
a commercial leavening agent containing yeast cells; used to raise the dough in making bread and for fermenting beer or whiskey
any of several compounds of barium
the commonest type of solidified lava; a dense dark grey fine-grained igneous rock that is composed chiefly of plagioclase feldspar and pyroxene
base metal
a metal that is common and not considered precious
base pair
one of the pairs of chemical bases joined by hydrogen bonds that connect the complementary strands of a DNA molecule or of an RNA molecule that has two strands; the base pairs are adenine with thymine and guanine with cytosine in DNA and adenine with uracil and guanine with cytosine in RNA
a phosphoric ester of a nucleoside; the basic structural unit of nucleic acids (DNA or RNA)
basic color
a dye that is considered to be a base because the chromophore is part of a positive ion
basic iron
pig iron containing a high percentage of phosphorus; used in making steel by a process that removes the phosphorus
basic slag
slag produced in making steel; low in silica but having large amounts of calcium phosphate; useful as fertilizer
a yellow-to-brown mineral that is a source of rare earth elements
bath water
water used for a bath
large mass of intrusive igneous rock believed to have solidified deep within the earth
bathroom tissue
a soft thin absorbent paper for use in toilets
battery acid
dilute sulfuric acid used in storage batteries
a clay-like mineral; the chief ore of aluminum; composed of aluminum oxides and aluminum hydroxides; used as an abrasive and catalyst
aromatic gum resin; similar to myrrh
a light strong brittle grey toxic bivalent metallic element
bearing brass
a brass bushing or a lining for a bearing
bearing metal
an alloy (often of lead or tin base) used for bearings
the pelt of a bear (sometimes used as a rug)
the soft brown fur of the beaver
beef tallow
tallow obtained from a bovine animal
a yellow to brown wax secreted by honeybees to build honeycombs
beet sugar
sugar made from sugar beets
bell metal
bronze with 3 or 4 parts copper to 1 part tin; used in making bells
Bengal kino
dried juice of the dhak tree; used as an astringent
an absorbent aluminum silicate clay formed from volcanic ash
a colorless liquid hydrocarbon; highly flammable; carcinogenic; the simplest of the aromatic compounds
any salt or ester of benzoic acid
benzoate of soda
a white crystalline salt used as a food preservative and antiseptic
a colorless oily compound extracted from coal tar and used in manufacturing synthetic resins
benzoic acid
a white crystalline solid occurring in many resins
any of a class of aromatic yellow compounds including several that are biologically important as coenzymes or acceptors or vitamins; used in making dyes
benzoyl group
the univalent radical derived from benzoic acid
benzoyl peroxide
a white crystalline peroxide used in bleaching (flour or oils or fats) and as a catalyst for free radical reactions
the univalent radical derived from toluene
the chief source of beryllium; colored transparent varieties are valued as gems
beryllium bronze
a copper-base alloy containing beryllium
beta endorphin
an endorphin produced by the pituitary gland that suppresses pain
beta globulin
a globulin in blood plasma that carries iron
beta iron
an allotrope of iron that is the same as alpha iron except that it is nonmagnetic; stable between 768 and 906 degrees centigrade
an isomer of carotene that is found in dark green and dark yellow fruits and vegetables
beta-hydroxybutyric acid
beta derivative of hydroxybutyric acid that is found in the blood and urine in some cases of impaired metabolism
enzyme produced by certain bacteria that inactivates penicillin and results in resistance to that antibiotic
an isomer of naphthol used in rubber as an antioxidant
a sweet tasting alkaloid that occurs in sugar beets
a transuranic element
a heavy brittle diamagnetic trivalent metallic element (resembles arsenic and antimony chemically); usually recovered as a by-product from ores of other metals
a salt of carbonic acid (containing the anion HCO3) in which one hydrogen atom has been replaced; an acid carbonate
bichloride of mercury
a white poisonous soluble crystalline sublimate of mercury; used as a pesticide or antiseptic or wood preservative
a compound containing two chlorine atoms per molecule
a salt of the hypothetical dichromic acid
bile acid
any of the steroid acids generated in the liver and stored with bile
bile salt
a salt of bile acid and a base; functions as an emulsifier of lipids and fatty acids
water accumulated in the bilge of a ship
an orange-yellow pigment in the bile that forms as a product of hemoglobin; excess amounts in the blood produce the yellow appearance observed in jaundice
material made by bonding together sheets of two different metals
binary compound
chemical compound composed of only two elements
something used to bind separate particles together or facilitate adhesion to a surface
binder board
a cardboard used by bookbinders to make covers for books
a biochemical catalyst such as an enzyme
plant materials and animal waste used as fuel
dark brown to black mica found in igneous and metamorphic rock
birch oil
a liquid ester with a strong odor of wintergreen; applied externally for minor muscle and joint pain
a sticky adhesive that is smeared on small branches to capture small birds
a water-soluble brownish-yellow pigment made by boiling wood soot
an acid tartrate; a hydrogen tartrate
bitter principle
any one of several hundred compounds having a bitter taste; not admitting of chemical classification
bitter spar
a light colored mineral consisting of calcium magnesium carbonate; a source of magnesium; used as a ceramic and as fertilizer
any of various naturally occurring impure mixtures of hydrocarbons
bituminous coal
rich in tarry hydrocarbons; burns readily with a smoky yellow flame
a radioactive transuranic element; discovered by bombarding americium with helium
black diamond
an inferior dark diamond used in industry for drilling and polishing
black ice
a thin coating of ice (as from freezing mist) on a road or sidewalk; nearly invisible but very hazardous
black lead
used as a lubricant and as a moderator in nuclear reactors
black opal
a dark colored opal with internal reflections of green or red
the atmosphere in a mine following an explosion; high in carbon dioxide and incapable of supporting life
a substance used to produce a shiny protective surface on footwear
a black bituminous material used for paving roads or other areas; usually spread over crushed rock
blanching agent
an agent that makes things white or colorless
bleach liquor
a solution containing bleaching agents that is used to bleach textiles or paper pulp
bleaching clay
an adsorbent clay that will remove coloring from oils
bleaching powder
a white powder comprised of calcium hydroxide and chloride and hypochlorite and used to bleach and/or disinfect
an ore that is the chief source of zinc; consists largely of zinc sulfide in crystalline form
blister copper
an impure form of copper having a black blistered surface
blistering agent
a toxic war gas with sulfide based compounds that raises blisters and attacks the eyes and lungs; there is no known antidote
blood agar
a culture medium containing whole blood as the nutrient
blood glucose
glucose in the bloodstream
blood platelet
tiny bits of protoplasm found in vertebrate blood; essential for blood clotting
green chalcedony with red spots that resemble blood
absorbent paper used to dry ink
blow gas
the gas leaving a generator during a blow period
an insulating layer of fat under the skin of whales and other large marine mammals; used as a source of oil
blue copperas
hydrated blue crystalline form of copper sulfate
used to whiten laundry or hair or give it a bluish tinge
blueprint paper
sensitized paper used to make blueprints
bluish-grey sandstone used for paving and building
solid excretory product evacuated from the bowels
a stout length of sawn timber; made in a wide variety of sizes and used for many purposes
body waste
waste matter (as urine or sweat but especially feces) discharged from the body
bog soil
poorly drained soils on top of peat and under marsh or swamp vegetation
a soft oily clay used as a pigment (especially a reddish brown pigment)
a superior quality of strong durable white writing paper; originally made for printing documents
bone ash
ash left when bones burn; high in calcium phosphate; used as fertilizer and in bone china
bone fat
fatty matter in bones extracted with solvents or by boiling or steaming; used chiefly in candles and cheap soaps and in lubricating greases
bone oil
the liquid portion of bone fat; used as a lubricant and in leather manufacture
the porous calcified substance from which bones are made
fertilizer made of ground bones
boracic acid
any of various acids containing boron and oxygen
a salt or ester of boric acid
an ore of boron consisting of hydrated sodium borate; used as a flux or cleansing agent
boric acid
a white or colorless slightly acid solid that is soluble in water and ethanol; used in the manufacture of glass and paper and adhesives and in detergents and as a flux in welding; also used as an antiseptic and food preservative
a mineral consisting of sulfides of copper and iron that is found in copper deposits
boron trifluoride
a pungent colorless gas
a salt of boric and silicic acids
bottled gas
hydrocarbon gases, usually propane or butane, kept under pressure
bottom fermenting yeast
brewer's yeast used in bottom fermentation of lager
potent bacterial toxin produced by the bacterium Clostridium botulinum that causes botulism; can be used as a bioweapon
botulinum toxin
any of several neurotoxins that are produced by the anaerobic bacterium Clostridium botulinum; causes muscle paralysis
botulinum toxin A
a neurotoxin (trade name Botox) that is used clinically in small quantities to treat strabismus and facial spasms and other neurological disorders characterized by abnormal muscle contractions; is also used by cosmetic surgeons to smooth frown lines temporarily
boulder clay
unstratified soil deposited by a glacier; consists of sand and clay and gravel and boulders mixed together
bouncing putty
a soft elastic silicone polymer that increases in elasticity with the application of force; used in the center of golf balls and as shock-absorbent padding
bowstring hemp
hemp obtained from the sansevieria
box calf
black calfskin leather tanned with chromium salts
a nonmetallic heavy volatile corrosive dark brown liquid element belonging to the halogens; found in sea water
brain sugar
a simple sugar found in lactose
broken husks of the seeds of cereal grains that are separated from the flour by sifting
a piece of wood that has been burned or is burning
an alloy of copper and zinc
the air that is inhaled and exhaled in respiration
a rudaceous rock consisting of sharp fragments embedded in clay or sand
brewer's yeast
yeast used in fermenting beer
bricks and mortar
building material consisting of bricks laid with mortar between them
an old name for sulfur
water containing salts
an antacid
Britannia metal
an alloy similar to pewter
the fur of a very young karakul lamb
the levorotatory form of dopa (trade names Bendopa and Brocadopa and Larodopa); as a drug it is used to treat Parkinson's disease
a red fluorescent dye resulting from the action of bromine on fluorescein; used in cosmetics and as a biological stain for studying cell structures
bromic acid
an unstable acid used as an oxidizing agent
any of the salts of hydrobromic acid; formerly used as a sedative but now generally replaced by safer drugs
an antacid
colorless liquid haloform CHBr3
bromophenol blue
a dye used as an acid-base indicator
bromothymol blue
a dye used as an acid-base indicator
an alloy of copper and tin and sometimes other elements; also any copper-base alloy containing other elements in place of tin
brown coal
intermediate between peat and bituminous coal
a reddish brown sandstone; used in buildings
a bitter alkaloid poison resembling strychnine and extracted from nux vomica
the wood from bushes or small branches
a spheroidal fullerene; the first known example of a fullerene
a soft yellowish suede leather originally from deerskin but now usually from sheepskin
a soft thick undyed leather from the skins of e.g. buffalo or oxen
(chemistry) an ionic compound that resists changes in its pH
buffer solution
a solution containing a buffer
a substance added to soaps or detergents to increase their cleansing action
building material
material used for constructing buildings
made by polymerizing butadiene
fine white Philippine fiber from stalks of unopened leaves of talipot palms; used in making hats
burnt lime
a white crystalline oxide used in the production of calcium hydroxide
burnt sienna
a reddish-brown pigment produced by roasting sienna
burnt umber
dark brown pigment obtained by heating umber
a gaseous hydrocarbon C4H6; used in making synthetic rubbers
occurs in natural gas; used in the manufacture of rubber and fuels
butanoic acid
an unpleasant smelling fatty acid found especially in butter
a flammable alcohol derived from butanes and used for solvents
colorless soluble flammable liquid ketone used as a solvent for resins and as a paint remover and in lacquers and cements and adhesives and cleaning fluids and celluloid
butcher paper
a strong wrapping paper that resists penetration by blood or meat fluids
any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers
the fatty substance of milk from which butter is made
a hydrocarbon radical (C4H9)
butyl rubber
synthetic rubber made by polymerizing isobutylene
any of three glycerides of butyric acid
an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds
one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
a base found in DNA and RNA and derived from pyrimidine; pairs with guanine
C-reactive protein
a byproduct of inflammation; a globulin that is found in the blood in some cases of acute inflammation
a colorless odorless alkane gas used as fuel
a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals
cabinet wood
moderately dense wood used for cabinetwork
a highly polished gem that is cut convexly but without facets
a poisonous oily liquid with a garlicky odor composed of 2 cacodyl groups; undergoes spontaneous combustion in dry air
a colorless toxic ptomaine with an unpleasant odor formed during the putrefaction of animal tissue
cadmium orange
orange-hued cadmium yellow pigment
cadmium sulfide
a yellow sulfide used chiefly as a pigment
cadmium sulphide
ore of cadmium; a rare yellowish mineral consisting of cadmium sulphide in crystalline form
cadmium yellow
pigment of cadmium sulfide and barium sulfate varying in hue from lemon yellow to orange
cadmium yellow pale
pale-hued cadmium yellow pigment
a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects
a smoky yellow or brown quartz
a white mineral; a common ore of zinc
a soft porous rock consisting of calcium carbonate deposited from springs rich in lime
a milky or greyish translucent to transparent quartz
a common mineral consisting of crystallized calcium carbonate; a major constituent of limestone
calcium bicarbonate
a bicarbonate that is a major cause of hard water
calcium carbide
a grey salt of calcium (CaC) used in making acetylene
calcium carbonate
a salt found in nature as chalk or calcite or aragonite or limestone
calcium chloride
a deliquescent salt; used in de-icing and as a drying agent
calcium hydrate
a caustic substance produced by heating limestone
calcium hydride
a saltlike binary compound (CaH2) used as a reducing agent and source of hydrogen
calcium hypochlorite
any hypochlorite of calcium; used as a bleaching agent
calcium lactate
a white crystalline salt made by the action of lactic acid on calcium carbonate; used in foods (as a baking powder) and given medically as a source of calcium
calcium nitrate
a deliquescent salt that is soluble in water; sometimes used as a source of nitrogen in fertilizers
calcium octadecanoate
an insoluble calcium salt of stearic acid and palmitic acid; it is formed when soap is mixed with water that contains calcium ions and is the scum produced in regions of hard water
calcium phosphate
a phosphate of calcium; a main constituent of animal bones
calcium sulfate
a white salt (CaSO4)
a compound used as a fertilizer and as a source of nitrogen compounds
fine leather from the skin of a calf
nitrate-bearing rock or gravel of the sodium nitrate deposits of Chile and Peru
crust or layer of hard subsoil encrusted with calcium-carbonate occurring in arid or semiarid regions
a tasteless colorless powder used medicinally as a cathartic
a resin obtained from the camphor tree; used in making celluloid and liniment
camphor oil
oil distilled from camphor resin
Canada balsam
yellow transparent exudate of the balsam fir; used as a transparent cement in optical devices (especially in microscopy) and as a mounting medium
an amino acid found in the jack bean
candelilla wax
a hard brown wax that occurs as a coating on candelilla shrubs
cane sugar
sucrose obtained from sugar cane
a resin obtained from the hemp plant; thought to be the active narcotic agent in marijuana
cannel coal
a bituminous coal that burns with a luminous flame
capric acid
a fatty acid found in animal oils and fats; has an unpleasant smell resembling goats
caproic acid
a fatty acid found in animal oils and fats or made synthetically; smells like goats
caprylic acid
a fatty acid having a rancid taste; found in butter and other fats and oils
colorless pungent crystalline compound derived from capsicum; source of the hotness of hot peppers of the genus Capsicum such as chili and cayenne and jalapeno
a salt (or ester) of carbamic acid
carbamic acid
an acid that is known only by virtue of its salts (as ammonium carbamate) or its esters (as urethane)
the chief solid component of mammalian urine; synthesized from ammonia and carbon dioxide and used as fertilizer and in animal feed and in plastics
a binary compound of carbon with a more electropositive element
an essential structural component of living cells and source of energy for animals; includes simple sugars with small molecules as well as macromolecular substances; are classified according to the number of monosaccharide groups they contain
carbolic acid
a toxic white soluble crystalline acidic derivative of benzene; used in manufacturing and as a disinfectant and antiseptic; poisonous if taken internally
an alloy based on tungsten with cobalt or nickel as a binder; used in making metal-cutting tools
carbon 14
a radioactive isotope of carbon
carbon atom
an atom of carbon
carbon black
a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink
carbon disulfide
a toxic colorless flammable liquid (CS2); used in the manufacture of rayon and cellophane and carbon tetrachloride and as a solvent for rubber
carbon nanotube
a fullerene molecule having a cylindrical or toroidal shape
carbon steel
steel whose characteristics are determined by the amount of carbon it contains
carbon tet
a colorless nonflammable liquid used as a solvent for fats and oils; because of its toxicity its use as a cleaning fluid or fire extinguisher has declined
carbon tetrahalide
compounds composed of 1 carbon and 4 halogen molecules
a thin paper coated on one side with a dark waxy substance (often containing carbon); used to transfer characters from the original to an under sheet of paper
a salt or ester of carbonic acid (containing the anion CO3)
carbonic acid
a weak acid known only in solution; formed when carbon dioxide combines with water
a compound containing metal combined with carbon monoxide
carbonyl group
the bivalent radical CO
an abrasive composed of silicon carbide crystals
the univalent radical -COOH; present in and characteristic of organic acids
carboxylic acid
an organic acid characterized by one or more carboxyl groups
carboxymethyl cellulose
an acid derivative of cellulose
deep-red cabochon garnet cut without facets
any substance that produces cancer
thin cardboard, usually rectangular
a stiff moderately thick paper
cardiac glucoside
obtained from a number of plants and used to stimulate the heart in cases of heart failure
a white or reddish mineral consisting of hydrous chlorides of potassium and magnesium; used as a fertilizer and as a source of potassium and magnesium
a translucent red or orange variety of chalcedony
a yellow radioactive mineral; an ore of uranium and radium and vanadium
yellow or orange-red fat-soluble pigments in plants
any of a class of highly unsaturated yellow to red pigments occurring in plants and animals
a colloidal extract from carrageen seaweed and other red algae
an inactive substance that is a vehicle for a radioactive tracer of the same substance and that assists in its recovery after some chemical reaction
cartridge brass
an alloy of copper and zinc (containing about 30% zinc) that is wrought into cartridges or tubing
cartridge paper
paper for making cartridge cases
cartridge paper
thick white paper for pencil and ink drawings
case-hardened steel
steel with a surface that is much harder than the interior metal
a milk protein used in making e.g. plastics and adhesives
casein glue
made from casein; used for e.g. plywood and cabinetwork
the wool of the Kashmir goat
any of a group of proteases that mediate apoptosis
a starch made by leaching and drying the root of the cassava plant; the source of tapioca; a staple food in the tropics
a hard heavy dark mineral that is the chief source of tin
cast iron
an alloy of iron containing so much carbon that it is brittle and so cannot be wrought but must be shaped by casting
cat's eye
any of various gems (as chrysoberyl or chalcedony) that reflect light when cut in a rounded shape
enzyme found in most plant and animal cells that functions as an oxidative catalyst; decomposes hydrogen peroxide into oxygen and water
a tannic acid that is extracted from black catechu as a white crystalline substance
any of a group of chemicals including epinephrine and norepinephrine that are produced in the medulla of the adrenal gland
cationic detergent
a class of synthetic detergents in which the surface-active part of the molecule is the cation
a waterproof filler and sealant that is used in building and repair to make watertight
any chemical substance that burns or destroys living tissue
caustic potash
a potassium compound often used in agriculture and industry
caustic soda
a strongly alkaline caustic used in manufacturing soap and paper and aluminum and various sodium compounds
a soft bluish-white ductile malleable toxic bivalent metallic element; occurs in association with zinc ores
a glycoprotein that is found primarily on the surface of helper T cells
a membrane glycoprotein that is found primarily on the surface of cytotoxic T cells
a ductile grey metallic element of the lanthanide series; used in lighter flints; the most abundant of the rare-earth group
a mineral consisting of strontium sulphate
highly flammable substance made from cellulose nitrate and camphor; used in e.g. motion-picture and X-ray film; its use has decreased with the development of nonflammable thermoplastics
a polysaccharide that is the chief constituent of all plant tissues and fibers
cellulose acetate
an ester of acetic acid; used in fibers and fabrics; photographic films and varnishes
cellulose ester
any ester of cellulose with an acid
cellulose nitrate
a nitric acid ester; used in lacquers and explosives
cellulose triacetate
cellulose acetate that is relatively slow to burn; used instead of celluloid for motion-picture film
cellulose xanthate
a cellulose ester obtained by treating cellulose with caustic soda
a plastic made from cellulose (or a derivative of cellulose)
a building material that is a powder made of a mixture of calcined limestone and clay; used with water and sand or gravel to make concrete and mortar
concrete pavement is sometimes referred to as cement
any of various materials used by dentists to fill cavities in teeth
something that hardens to act as adhesive material
a chemical compound that is a constituent of steel and cast iron; very hard and brittle
a fibrous scleroprotein that occurs in the outer layer of the skin and in horny tissues such as hair, feathers, nails, and hooves
a white wax extracted from ozokerite
cerotic acid
a white solid fatty acid found in waxes (such as beeswax)
cerulean blue
light greenish-blue pigment consisting essentially of oxides of cobalt and tin
a soft yellow wax secreted by glands in the ear canal
a poisonous white pigment that contains lead
a mineral consisting of lead carbonate that is an important source of lead
cesium 137
a radioactive isotope of cesium used in radiation therapy
a cationic detergent that is a powerful disinfectant
a dark-colored spinel containing iron
a radioactive transuranic element; discovered by bombarding curium with alpha particles
a fluorocarbon with chlorine; formerly used as a refrigerant and as a propellant in aerosol cans
a group of minerals of the zeolite family consisting of a hydrous silicate of calcium and aluminum
a small piece of paper that is supposed to be removed when a hole is punched in a card or paper tape
material consisting of seed coverings and small pieces of stem or leaves that have been separated from the seeds
a heavy grey mineral that is an ore of copper
a yellow copper ore (CuFeS2) made up of copper and iron sulfide
a soft whitish calcite
chalk dust
dust resulting from writing with a piece of chalk
a deposit of urates around a joint or in the external ear; diagnostic of advanced or chronic gout
iron ore in the form of ferrous carbonate
a soft suede leather formerly from the skin of the chamois antelope but now from sheepskin
a greenish grey or black silicate of iron and aluminum
a charred substance
a carbonaceous material obtained by heating wood or other organic matter in the absence of air
chaulmoogra oil
an oil from chaulmoogra trees; used in treatment of skin diseases and leprosy
a heterocyclic compound having a metal ion attached by coordinate bonds to at least two nonmetal ions
chemical agent
an agent that produces chemical reactions
chemical compound
(chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight
chemical element
any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
chemical group
(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
chemical irritant
a substance producing irritation
Chemical Mace
(trademark) a liquid that temporarily disables a person; prepared as an aerosol and sprayed in the face, it irritates the eyes and causes dizziness and immobilization
material produced by or used in a reaction involving changes in atoms or molecules
the chemical composition and properties of a substance or object
cheoplastic metal
any alloy that fuses at low temperatures and can be used molding artificial teeth
chernozemic soil
a rich black loam of Russia
cherry-tree gum
exudation from trees of the Prunus genus; resembles gum arabic
variety of silica containing microcrystalline quartz
Chian turpentine
a turpentine exuded by the terebinth
chicken manure
chicken excreta used as fertilizer
gum-like substance from the sapodilla
china clay
a fine usually white clay formed by the weathering of aluminous minerals (as feldspar); used in ceramics and as an absorbent and as a filler (e.g., in paper)
the expensive silvery grey fur of the chinchilla
Chinese white
a white pigment used in house paints; consists of zinc oxide
Chinese wood oil
a yellow oil obtained from the seeds of the tung tree
a cheap hard material made from wood chips that are pressed together and bound with synthetic resin
chisel steel
steel used in making chisels
a tough semitransparent horny substance; the principal component of the exoskeletons of arthropods and the cell walls of certain fungi
any salt of chloric acid
chloric acid
(HClO3) a strong unstable acid with an acrid odor found in chlorate salts
any salt of hydrochloric acid (containing the chloride ion)
any compound containing a chlorine atom
chlorine dioxide
an explosive gas (ClO2) used chiefly in bleaching paper or starch or soap or flour and in water purification
chlorine water
an aqueous solution of chlorine used as a bleaching agent
a generally green or black mineral; it occurs as a constituent of many rocks typically in the form of a flat crystal
a colorless volatile flammable liquid with an almond odor that is made from chlorine and benzene; used as a solvent and in the production of phenol and DDT and other organic compounds
chlorohydric acid
an aqueous solution of hydrogen chloride; a strongly corrosive acid
a heavy colorless insoluble liquid compound that causes tears and vomiting; used as a pesticide and as tear gas
derivative of butadiene used in making neoprene by polymerization
chlorous acid
(HClO2) a strongly oxidizing acid; known only in solution
a common organophosphate insecticide
an animal sterol that is normally synthesized by the liver; the most abundant steroid in animal tissues
cholic acid
an insoluble crystalline acid present in bile
a B-complex vitamin that is a constituent of lecithin; essential in the metabolism of fat
an enzyme that hydrolyses acetylcholine (into choline and acetic acid)
a substance that resembles gelatin and is obtained by boiling cartilage in water
Christmas factor
coagulation factor whose absence is associated with hemophilia B
any salt or ester of chromic acid
another word for chromium when it is used in dyes or pigments
chrome alum
a violet-colored salt used in hide tanning and as a mordant in dyeing
chrome green
any of a class of green pigments consisting of chrome yellow and iron blue
chrome yellow
any of several yellow pigments consisting of normal lead chromate and other lead compounds
chrome-tungsten steel
a steel alloy made with chromium and tungsten
chromic acid
an unstable acid known only in solution and as chromate salts
a brownish-black mineral; the major source of chromium
chromium steel
steel containing chromium that makes it resistant to corrosion
a compound that can be converted to a pigment
the chemical group that gives color to a molecule
a rare hard yellow green mineral consisting of beryllium aluminate in crystal form; used as a gemstone
a brown or yellow-green olivine found in igneous and metamorphic rocks and used as a gemstone
a green variety of chalcedony valued as a gemstone
a grey or green fibrous mineral; an important source of commercial asbestos
a microscopic particle of triglycerides produced in the intestines during digestion; in the bloodstream they release their fatty acids into the blood
a semiliquid mass of partially digested food that passes from the stomach through the pyloric sphincter into the duodenum
an enzyme that occurs in gastric juice; causes milk to coagulate
cigarette paper
a strong tissue paper that burns evenly and is sufficiently porous to control the burning of the tobacco in a cigarette
an alkaloid derivative of the bark of cinchona trees that is used as an antimalarial drug
cinder pig
pig iron containing a substantial proportion of slag
a heavy reddish mineral consisting of mercuric sulfide; the chief source of mercury
a colorless oily liquid; the monomer for polystyrene
cinnamon stone
a garnet ranging in color from yellow to brown
a salt or ester of citric acid
citric acid
a weak water-soluble acid found in many fruits (especially citrus fruits); used as a flavoring agent
semiprecious yellow quartz resembling topaz
an amino acid that does not occur in proteins but is an intermediate in the conversion of ornithine to arginine
a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water)
a long thin board with one edge thicker than the other; used as siding by lapping one board over the board below
a very fine-grained soil that is plastic when moist but hard when fired
water soaked soil; soft wet earth
fine-grained rock consisting of compacted clay particles
a commercial bleaching agent
Clostridium perfringens epsilon toxin
a bacterial toxin produced by clostridium perfringens; causes intense abdominal cramps and diarrhea that begins 8-22 hours after consumption of foods containing large numbers of these bacteria
clotting factor
any of the factors in the blood whose actions are essential for blood coagulation
clove oil
essential oil obtained from cloves and used to flavor medicines
hardened clay
a radioactive transuranic metallic element; produced by bombarding plutonium with helium nuclei
CN gas
a tear gas that is weaker than CS gas but lasts longer
a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition
an odorless very poisonous gas that is a product of incomplete combustion of carbon
a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis
an agent that produces coagulation
an enzyme that induces coagulation
fossil fuel consisting of carbonized vegetable matter deposited in the Carboniferous period
coal gas
gaseous mixture produced by distillation of bituminous coal and used for heating and lighting
coal oil
a flammable hydrocarbon oil used as fuel in lamps and heaters
coal tar
a tar formed from distillation of bituminous coal; coal tar can be further distilled to give various aromatic compounds
coal-tar creosote
a dark oily liquid obtained by distillation of coal tar; used as a preservative for wood
cobalt 60
a radioactive isotope of cobalt with mass number 60; a source of exceptionally intense gamma rays; used in radiation therapy
cobalt bloom
a reddish mineral consisting of hydrated cobalt arsenate in monoclinic crystalline form and used in coloring glass; usually found in veins bearing cobalt and arsenic
cobalt blue
greenish-blue pigment consisting essentially of cobalt oxide and alumina
a rare silvery-white mineral; important ore of cobalt
a coenzyme important in respiration in the Krebs cycle
a red dyestuff consisting of dried bodies of female cochineal insects
cocoa butter
a yellow-white fat from cocoa beans
cod liver oil
an oil obtained from the livers of cod and similar fishes; taken orally as a source of vitamins A and D
cod oil
an inferior cod-liver oil that is used in leather manufacturing
coding DNA
sequence of a gene's DNA that transcribes into protein structures
a specific sequence of three adjacent nucleotides on a strand of DNA or RNA that specifies the genetic code information for synthesizing a particular amino acid
a small molecule (not a protein but sometimes a vitamin) essential for the activity of some enzymes
coenzyme A
a coenzyme present in all living cells; essential to metabolism of carbohydrates and fats and some amino acids
coenzyme Q
any of several quinones found in living cells and that function as coenzymes that transfer electrons from one molecule to another in cell respiration
a substance (as a coenzyme) that must join with another to produce a given result
coin silver
a silver of the degree of purity established for making legal silver coins
carbon fuel produced by distillation of coal
cold rubber
a rubber made at low temperatures (5 degrees Centigrade) which is tougher than conventional rubber and is often used in car tires
any enzyme that catalyzes the hydrolysis of collagen and gelatin
a colorless syrupy solution of pyroxylin in ether and alcohol; used as a coating for wounds or photographic films
a mixture with properties between those of a solution and fine suspension
colloidal gel
a colloid in a more solid form than a sol
colloidal solution
a colloid that has a continuous liquid phase in which a solid is suspended in a liquid
translucent brittle substance produced from pine oleoresin; used especially in varnishes and inks and on the bows of stringed instruments
any material used for its color
a valuable black mineral combining niobite and tantalite; used in cell phones and computer chips
a black mineral that is an ore of niobium and tantalum
a former name for niobium
a substance that can be burned to provide heat or power
common salt
a white crystalline solid consisting mainly of sodium chloride (NaCl)
common topaz
a yellow quartz
one of a series of enzymes in the blood serum that are part of the immune response
complementary DNA
single-stranded DNA that is complementary to messenger RNA or DNA that has been synthesized from messenger RNA by reverse transcriptase
a compound described in terms of the central atom to which other atoms are bound or coordinated
composite material
strong lightweight material developed in the laboratory; fibers of more than one kind are bonded together chemically
a mixture of ingredients
a mixture of decaying vegetation and manure; used as a fertilizer
compound protein
a protein complex combining amino acids with other substances
compressed air
air at a pressure greater than that of the atmosphere
compressed gas
gas at a high pressure that can be used as a propellant
computer paper
paper folded to permit continuous printing controlled by a computer
the desired mineral that is left after impurities have been removed from mined ore
a strong hard building material composed of sand and gravel and cement and water
a product of condensation
a substance that readily conducts e.g. electricity and heat
a minor chemical constituent that gives a wine or liquor its distinctive character
a composite rock made up of particles of varying size
congo copal
copal found usually as a fossil
congo red
a red-brown azo dye especially as a chemical pH indicator (congo red is red in basic and blue in acidic solutions)
a gum resin from the poison hemlock, Conium maculatum
a mixture of two partially miscible liquids A and B produces two conjugate solutions: one of A in B and another of B in A
construction paper
paper suitable for drawing and making cutouts
a substance that contaminates
contrast material
a substance that is opaque to x-rays; when administered it allows a radiologist to examine the organ or tissue it fills
a fluid agent (gas or liquid) that produces cooling; especially one used to cool a system by transferring heat away from one part to another
a brittle aromatic resin used in varnishes
partly mineralized copal dug from the ground
a polymer consisting of two or more different monomers
copper oxide
an oxide of copper
copper sulfate
a copper salt made by the action of sulfuric acid on copper oxide
copper-base alloy
any alloy whose principal component is copper
the hard stony skeleton of a Mediterranean coral that has a delicate red or pink color and is used for jewelry
a blue mineral of magnesium and iron and aluminum and silicon and oxygen; often used as a gemstone
a fine leather originally made in Cordoba, Spain
firewood cut and stacked in cords; wood sold by the cord
outer bark of the cork oak; used for stoppers for bottles etc.
(botany) outer tissue of bark; a protective layer of dead cells
a heat-insulating building material consisting of cork granules that are made into sheets by compressing and baking
corn snow
granular snow formed by alternate thawing and freezing
corn sugar
dextrose made by hydrolysis of cornstarch
starch prepared from the grains of corn; used in cooking as a thickener
a substance having the tendency to cause corrosion (such a strong acids or alkali)
corrugated board
cardboard with corrugations (can be glued to flat cardboard on one or both sides)
secreted by the adrenal cortex; involved in regulating water and electrolyte balance in the body
Cortone Acetate
a corticosteroid hormone (trade name Cortone Acetate) normally produced by the adrenal cortex; is converted to hydrocortisone
very hard mineral used as an abrasive
costus oil
a yellow volatile essential oil obtained from costusroot; used in perfumes
cotton cake
the solid matter remaining after oil has been pressed from cottonseeds
soft silky fibers from cotton plants in their raw state
coumarone resin
a thermoplastic resin obtained by polymerization of indene and coumarone; used in coatings and paint and asphalt tile
a stain of contrasting color that is used when the principal stain does not show the structure clearly
covering material
a material used by builders to cover surfaces
cow manure
cow excreta used as fertilizer
cow pie
fecal matter of a cow
the hide of a cow
leather made from the hide of a cow
either of two related enzymes that control the production of prostaglandins and are blocked by aspirin
an enzyme that regulates prostaglandins that are important for the health of the stomach lining and kidneys
an enzyme that makes prostaglandins that cause inflammation and pain and fever
a hard brittle multivalent metallic element; resistant to corrosion and tarnishing
the residue that remains after animal fat has been rendered
obscene terms for feces
Crazy Glue
a commercial brand of epoxy glue
cream of tartar
a salt used especially in baking powder
an amino acid that does not occur in proteins but is found in the muscle tissue of vertebrates both in the free form and as phosphocreatine; supplies energy for muscle contraction
creatine phosphate
an organic compound of creatine and phosphoric acid; found in the muscles of vertebrates where its hydrolysis releases energy for muscular contraction
a colorless to yellow aromatic liquid that is a constituent of creosote
a colorless or yellowish oily liquid obtained by distillation of wood tar; used as an antiseptic
crepe rubber
crude natural rubber; used mainly for shoe soles
paper with a crinkled texture; usually colored and used for decorations
any of three poisonous colorless isomeric phenols; derived from coal or wood tar; used as a disinfectant
a white mineral consisting of silica; found in volcanic rocks
a rare lead chromite mineral that forms bright orange crystals
crown glass
a glass blown into a globe which is later flattened and spun to form a disk
crown glass
optical glass of low dispersion and low refractive index
crucible steel
steel made by the mixture of molten wrought iron, charcoal, and other substances in a crucible
heavy wet snow that is unsuitable for skiing
any substance considered disgustingly foul or unpleasant
a dark oil consisting mainly of hydrocarbons
leather that has had its grain pattern accentuated
crushed rock
rock fragments and pebbles
a liquid that boils at below -160 C and is used as a refrigerant
a solid formed by the solidification of a chemical and having a highly regular atomic structure
crystal violet
a green crystal (violet in water) used as a dye or stain or bactericide or fungicide or anthelmintic or burn treatment
colorless glass made of almost pure silica
a soft silver-white ductile metallic element (liquid at normal temperatures); the most electropositive and alkaline metal
CS gas
a tear gas that is stronger than CN gas but wears off faster; can be deployed by grenades or cluster bombs; can cause skin burns and fatal pulmonary edema
a ductile malleable reddish-brown corrosion-resistant diamagnetic metallic element; occurs in various minerals but is the only metal that occurs abundantly in large masses; used as an electrical and thermal conductor
culture medium
(bacteriology) a nutrient substance (solid or liquid) that is used to cultivate micro-organisms
cupric acetate
a blue or green powder used as a paint pigment
a mineral consisting of cuprous oxide that is a source of copper
a 60/40 alloy of copper and nickel
a toxic alkaloid found in certain tropical South American trees that is a powerful relaxant for striated muscles
(biochemistry) a waxy transparent material that occurs in the cuticle of plants and consists of highly polymerized esters of fatty acids
a weak soluble dibasic acid (the parent acid of cyanamide salts)
cyanic acid
a colorless poisonous volatile liquid acid that hydrolyzes readily to ammonia and carbon dioxide
an extremely poisonous salt of hydrocyanic acid
cyanide group
the monovalent group -CN in a chemical compound
any of a class of organic compounds containing the cyano radical -CN
cyanine dye
any of a class of dyes containing a -CH= group linking two heterocyclic rings containing nitrogen; used as sensitizers in photography
a grey or greenish-blue mineral consisting of aluminum silicate in crystalline form; occurs in metaphoric rock, used as a refractory
a colorless toxic gas with a pungent almond odor; has been used in chemical warfare
any organic compound in which the cyano radical -CN and the hydroxyl radical -OH are attached to the same carbon atom
a white crystalline organic base; used mainly in making melamine resins
cyanuric acid
a trimer of cyanic acid
a colorless oily alcohol that smells like camphor
cyclohexanol phthalate
the cyclohexanol ester of phthalic acid
any of three isotopes of a colorless aromatic liquid hydrocarbon occurring in the volatile oil of cumin and thyme and used in the manufacture of synthetic resins
an amino acid containing sulfur that is found in most proteins; oxidizes on exposure to air to form cystine
a crystalline amino acid found in proteins (especially keratin); discovered in bladder stones
a nucleoside component of DNA; composed of cytosine and deoxyribose
(biochemistry) a class of hemoprotein whose principal biological function is electron transfer (especially in cellular respiration)
cytochrome c
the most abundant and stable cytochrome; involved in energy transfer
any of various protein molecules secreted by cells of the immune system that serve to regulate the immune system
any of a class of plant hormones that promote cell division and delay the senescence of leaves
a substance that partly or completely destroys animal cells
any substance that has a toxic effect on cells
a grey volcanic rock containing plagioclase and quartz and other crystalline minerals
any of various hard resins from trees of the family Dipterocarpaceae and of the genus Agathis; especially the amboyna pine
Damascus steel
a hard resilient steel often decorated and used for sword blades
a variety of muscovite
dark matter
(cosmology) a hypothetical form of matter that is believed to make up 90 percent of the universe; it is invisible (does not absorb or emit light) and does not collide with atomic particles but exerts gravitational force
material used to daub walls
Davy's grey
slightly purplish or bluish dark grey
a transuranic element
an insecticide that is also toxic to animals and humans; banned in the United States since 1972
an enzyme that removes the iodine radical
DEAE cellulose
used for chromatography
a plank of softwood (fir or pine board)
wood that is easy to saw (from conifers such as pine or fir)
the remains of something that has been destroyed or broken up
decanedioic acid
a dicarboxylic acid used to make resins
any of the enzymes that hydrolize the carboxyl group
leather from the hide of a deer
a chemical that is sprayed on plants and causes their leaves to fall off
delta iron
an allotrope of iron that is stable between 1403 degrees centigrade and the melting point (= 1532 degrees)
a green andradite used as a gemstone
a light brown raw cane sugar from Guyana
any substance that serves as a denaturing agent
denatured alcohol
ethyl alcohol that is unfit for drinking but is still useful for other purposes
dental gold
an alloy of gold used in dentistry
a calcareous material harder and denser than bone that comprises the bulk of a tooth
a nucleoside component of DNA; composed of adenosine and deoxyribose
a nucleoside component of DNA; composed of guanine and deoxyribose
a sugar that is a constituent of nucleic acids
a nucleoside component of DNA; composed of thymine and deoxyribose
a chemical (usually a sulfide) used to remove hair or wool or bristles from hides
a compound obtained from, or regarded as derived from, another compound
diesel oil used in cars and lorries with diesel engines; from d(iesel) e(ngine) r(oad) v(ehicle)
a potent estrogen used in medicine and in feed for livestock and poultry
desert soil
a type of soil that develops in arid climates
a substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)
a surface-active chemical widely used in industry and laundering
loose material (stone fragments and silt etc) that is worn away from rocks
deuterium oxide
water containing a substantial proportion of deuterium atoms, used in nuclear reactors
an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)
water that has condensed on a cool surface overnight from water vapor in the air
Dexamethasone Intensol
a corticosteroid drug (trade names Decadron or Dexamethasone Intensol or Dexone or Hexadrol or Oradexon) used to treat allergies or inflammation
any of various polysaccharides obtained by hydrolysis of starch; a tasteless and odorless gummy substance that is used as a thickening agent and in adhesives and in dietary supplements
an isomer of glucose that is found in honey and sweet fruits
tyrosine with two iodine atoms added
a substance that exhibits diamagnetism
any organic compound containing two amino groups
diatomaceous earth
a light soil consisting of siliceous diatom remains and often used as a filtering material
the univalent cation R-N:N- (where R is an aromatic hydrocarbon); found in salts that are used in manufacturing azo dyes
dibasic acid
an acid containing two replaceable hydrogen atoms per molecule
dibasic salt
a salt derived by replacing two hydrogen atoms per molecule
a nonflammable liquid used as a solvent and paint remover and refrigerant
dichromic acid
the hypothetical acid (H2Cr2O7) from which dichromates are derived; known only in solution and in the form of dichromate salts
a material such as glass or porcelain with negligible electrical or thermal conductivity
diesel fuel
a heavy mineral oil used as fuel in diesel engines
any substance that promotes digestion
a powerful cardiac stimulant obtained from foxglove
dihydric alcohol
any of a class of alcohols having 2 hydroxyl groups in each molecule
amino acid that is formed in the liver and converted into dopamine in the brain
a diluting agent
a diluted solution
a compound whose molecules are composed of two identical monomers
a compound used in analysis as a precipitant for palladium or nickel
a chad that has been punched or dimpled but all four corners are still attached
a granular crystalline intrusive rock
an oxide containing two atoms of oxygen in the molecule
any of several toxic or carcinogenic hydrocarbons that occur as impurities in herbicides
Dippel's oil
dark-colored ill-smelling oil obtained by carbonizing bone; used especially in sheep dips and in denaturing alcohol
direct dye
dye with a high affinity for cellulose fibers (cotton or rayon etc.)
the part of the earth's surface consisting of humus and disintegrated rock
an enzyme that catalyzes the hydrolysis of disaccharides into monosaccharides
any of a variety of carbohydrates that yield two monosaccharide molecules on complete hydrolysis
a substance that is emitted or released
water in which dishes and cooking utensils are washed
dispersed particles
(of colloids) a substance in the colloidal state
dispersing medium
(of colloids) a substance in which another is colloidally dispersed
a liquid substance capable of dissolving other substances
a purified liquid produced by condensation from a vapor during distilling; the product of distilling
distilled water
water that has been purified by distillation
(biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information
DNA polymerase
the enzyme responsible for DNA replication
docosahexaenoic acid
an omega-3 fatty acid with 22 carbon atoms; found in fish (especially tuna and bluefish)
dodecanoic acid
a crystalline fatty acid occurring as glycerides in natural fats and oils (especially coconut oil and palm-kernel oil)
soft leather from deerskin or lambskin
a kind of sedimentary rock resembling marble or limestone but rich in magnesium carbonate
dolphin oil
an unsaturated fatty oil obtained from dolphins and used as a fine lubricant
domoic acid
a neurotoxin that is deadly for humans; found in various marine algae
the residue of partially burnt tobacco left caked in the bowl of a pipe after smoking
double salt
a solution of two simple salts that forms a single substance on crystallization
dragon's blood
a dark red resinous substance derived from various trees and used in photoengraving
drawing paper
paper that is specially prepared for use in drafting
wood that is floating or that has been washed ashore
drill rod
carbon steel used for rock drills and dowels
drilling fluid
a mixture of clays and chemicals and water; pumped down the drill pipe to lubricate and cool the drilling bit and to flush out the cuttings and to strengthen the sides of the hole
the form of calcium carbonate found in stalactites and stalagmites
fecal matter of animals
worthless or dangerous material that should be removed
the scum formed by oxidation at the surface of molten metals
dry ice
solidified carbon dioxide; dry ice sublimates at -78.5 C and is used mainly as a refrigerant
drying oil
an oil that hardens in air due to oxidation and is often used as a paint or varnish base
a radioactive transuranic element
double-stranded cDNA
tallow mixed with oil; used to make leather soft and waterproof
an androgen (trade names Durabolin or Kabolin) that is used to treat testosterone deficiency or breast cancer or osteoporosis
an aluminum-based alloy
fine powdery material such as dry earth or pollen that can be blown about in the air
free microscopic particles of solid material
a trivalent metallic element of the rare earth group; forms compounds that are highly magnetic
a usually soluble substance for staining or coloring e.g. fabrics or hair
any wood from which dye is obtained
once thought to be one of four elements composing the universe (Empedocles)
earth color
a colored mineral used as a pigment
the loose soft material that makes up a large part of the land surface
eau de Javelle
an aqueous solution of sodium hypochlorite
a hard nonresilient rubber formed by vulcanizing natural rubber
(spiritualism) a substance supposed to emanate from the body of the medium during a trance
a complex molecule used medically to chelate metal ions in cases of lead or heavy metal poisoning
water mixed with waste matter
a foul-smelling outflow or vapor (especially a gaseous waste)
eicosapentaenoic acid
an omega-3 fatty acid with 20 carbon atoms; found in fish (especially tuna and bluefish)
elaeostearic acid
a crystalline unsaturated fatty acid
elaidic acid
a monounsaturated fatty acid that has the same structure as oleic acid except that it is a trans fatty acid; the major trans fatty acid in margarine and fried foods
a pancreatic enzyme that catalyzes the hydrolysis of elastin
any of various elastic materials that resemble rubber (resumes its original shape when a deforming force is removed)
a solution that conducts electricity
an alloy of gold and silver
one of four substances thought in ancient and medieval cosmology to constitute the physical universe
Elinvar is a trademark for a kind of steel used for watch springs because its elasticity is constant over a wide range of temperatures
a sweet flavored liquid (usually containing a small amount of alcohol) used in compounding medicines to be taken by mouth in order to mask an unpleasant taste
hypothetical substance that the alchemists believed to be capable of changing base metals into gold
a liquid solution that results from elution
something that is emitted or radiated (as a gas or an odor or a light, etc.)
a green transparent form of beryl; highly valued as a gemstone
a hard grey-black mineral consisting of corundum and either hematite or magnetite; used as an abrasive (especially as a coating on paper)
emery cloth
cloth covered with powdered emery
emery paper
stiff paper coated with powdered emery or sand
emery rock
a mixture of emery dust and a binder; can be molded into grindstones
any agent that promotes menstrual discharge
a surface-active agent that promotes the formation of an emulsion
(chemistry) a colloid in which both phases are liquids
a colored glassy compound (opaque or partially opaque) that is fused to the surface of metal or glass or pottery for decoration or protection
an amine containing the double bond linkage -C=C-N-
either one of a pair of compounds (crystals or molecules) that are mirror images on each other but are not identical
a nuclease that cleaves nucleic acids at interior bonds and so produces fragments of various sizes
a neurochemical occurring naturally in the brain and having analgesic properties
a toxin that is confined inside the microorganisms and is released only when the microorganisms are broken down or die
an endorphin having opiate qualities that occurs in the brain and spinal cord and elsewhere
an organic compound that contains a hydroxyl group bonded to a carbon atom which in turn is doubly bonded to another carbon atom
enzyme in the intestinal juice that converts inactive trypsinogen into active trypsin
a cytotoxin specific for the cells of the intestinal mucosa
any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions
white odorless powdered or crystalline alkaloid from plants of the genus Ephedra (especially Ephedra sinica) or made synthetically; used as a bronchodilator to treat bronchitis and asthma
DNA that is not incorporated into the genome but is replicated together with the genome (especially in bacterial cells)
a thermosetting resin; used chiefly in strong adhesives and coatings and laminates
Epsom salts
hydrated magnesium sulfate that is taken orally to treat heartburn and constipation and injected to prevent seizures
a trivalent metallic element of the rare earth group; occurs with yttrium
a plant sterol that is converted into vitamin D by ultraviolet radiation
an alkaloid derived from ergot that is less toxic than ergot; causes constriction of blood vessels and is used to treat migraine
Ergotrate Maleate
an alkaloid derived from ergot (trade name Ergotrate Maleate) that is less toxic than ergot; induces muscular contraction of the uterus and is administered after childbirth or abortion
the expensive white fur of the ermine
any substance that can cause lysis (destruction) of erythrocytes (red blood cells) and the release of their hemoglobin
a glycoprotein secreted by the kidneys that stimulates the production of red blood cells
a radioactive transuranic element produced by bombarding plutonium with neutrons
any substance possessing to a high degree the predominant properties of a plant or drug or other natural product from which it is extracted
essential amino acid
an amino acid that is required by animals but that they cannot synthesize; must be supplied in the diet
essential oil
an oil having the odor or flavor of the plant from which it comes; used in perfume and flavorings
organic compound formed by reaction between an acid and an alcohol with elimination of water
the most powerful female hormone that occurs naturally; synthesized and used to treat estrogen deficiency and breast cancer
a naturally occurring estrogenic hormone; a synthetic form is used to treat estrogen deficiency
a general term for female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics
a naturally occurring weak estrogenic hormone secreted by the mammalian ovary; synthesized (trade name Estronol) and used to treat estrogen deficiency
ethanal trimer
a colorless liquid (a cyclic trimer of acetaldehyde) that is used as a sedative and a solvent
ethanedioic acid
a toxic colorless crystalline organic acid found in oxalis and other plants; used as a bleach and rust remover and in chemical analysis
a sweet but poisonous syrupy liquid used as an antifreeze and solvent
the intoxicating agent in fermented and distilled liquors; used pure or denatured as a solvent or in medicines and colognes and cleaning solutions and rocket fuel; proposed as a renewable clean-burning additive to gasoline
a flammable colorless gaseous alkene; obtained from petroleum and natural gas and used in manufacturing many other chemicals; sometimes used as an anesthetic
any of a class of organic compounds that have two hydrocarbon groups linked by an oxygen atom
the fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies
ethyl acetate
a fragrant colorless flammable volatile liquid ester made from ethanol and acetic acid; used in flavorings and perfumes and as a solvent for plastics
the univalent hydrocarbon radical C2H5 derived from ethane by the removal of one hydrogen atom
a bivalent and trivalent metallic element of the rare earth group
eucalyptus oil
an essential oil obtained from the leaves of eucalypts
an acrid brown gum resin now used mainly in veterinary medicine
an alloy of copper and nickel with high electrical resistance and a low temperature coefficient; used as resistance wire
a mixture of substances having a minimum melting point
eutectoid steel
a steel that contains 0.9% carbon (the eutectic point); a carbon steel with 0.9% carbon is pure pearlite
the sediment that is left after the evaporation of seawater
thin curly wood shavings used for packing or stuffing
exhaled breath
gases ejected from an engine as waste products
a nuclease that releases one nucleotide at a time (serially) beginning at one of a nucleic acid
a compound that gives off heat during its formation and absorbs heat during its decomposition
a toxin that is secreted by microorganisms into the surrounding medium
a solution obtained by steeping or soaking a substance (usually in water)
an extravasated liquid (blood or lymph or urine); the product of extravasation
a substance that oozes out from plant pores
a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite
facial tissue
tissue paper suitable for use on the face
factor I
a protein present in blood plasma; converts to fibrin when blood clots
factor II
a protein in blood plasma that is the inactive precursor of thrombin
factor III
an enzyme liberated from blood platelets that converts prothrombin into thrombin as blood starts to clot
factor IV
ion of calcium; a factor in the clotting of blood
factor V
a coagulation factor
factor VII
a coagulation factor formed in the kidney under the influence of vitamin K
factor VIII
a coagulation factor (trade name Hemofil) whose absence is associated with hemophilia A
factor X
coagulation factor that is converted to an enzyme that converts prothrombin to thrombin in a reaction that depends on calcium ions and other coagulation factors
factor XI
coagulation factor whose deficiency results in a hemorrhagic tendency
factor XIII
in the clotting of blood thrombin catalyzes factor XIII into its active form (fibrinase) which causes fibrin to form a stable clot
the radioactive particles that settle to the ground after a nuclear explosion
a soft greasy substance occurring in organic tissue and consisting of a mixture of lipids (mostly triglycerides)
fat-soluble vitamin
any vitamin that is soluble in fats
fatty acid
any of a class of aliphatic monocarboxylic acids that form part of a lipid molecule and can be derived from fat by hydrolysis; fatty acids are simple molecules built around a series of carbon atoms linked together in a chain of 12 to 22 carbon atoms
fatty oil
nonvolatile animal or plant oil
a heavy ductile magnetic metallic element; is silver-white in pure form but readily rusts; used in construction and tools and armament; plays a role in the transport of oxygen by the blood
excreta (especially of insects)
the raw material that is required for some industrial process
Fehling's solution
a liquid solution of copper sulfate and potassium tartrate and sodium hydroxide that is used to test for sugar in the urine; solution turns reddish when sugar is present
any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium
the dressed skin of an animal (especially a large animal)
material for building fences
a dark mineral consisting of oxides of yttrium and erbium and tantalum and other minerals
a substance capable of bringing about fermentation
ferric oxide
a red oxide of iron
ferricyanic acid
a brown unstable acid formed from ferricyanide
salt of ferricyanic acid obtained by oxidation of a ferrocyanide
a solid solution in which alpha iron is the solvent
a protein containing 20% iron that is found in the intestines and liver and spleen; it is one of the chief forms in which iron is stored in the body
a pyrophoric alloy of iron with cerium; used for lighter flints
concrete with metal and/or mesh added to provide extra support against stresses
ferrocyanic acid
a white unstable acid formed from ferrocyanide salts
salt of ferrocyanic acid usually obtained by a reaction of a cyanide with iron sulphate
any substance such as manure or a mixture of nitrates used to make soil more fertile
any of several antigens that occur naturally in the fetus and sometimes in adults with cancer
a slender and greatly elongated substance capable of being spun into yarn
a covering material made of glass fibers in resins
a very slender natural or synthetic fiber
a white insoluble fibrous protein formed by the action of thrombin on fibrinogen when blood clots; it forms a network that traps red cells and platelets
an enzyme that dissolves the fibrin of blood clots
peptide released from the amino end of fibrinogen by the action of thrombin to form fibrin during clotting of the blood
stone that occurs naturally in fields; often used as building material
fig wax
a hard cream-colored wax obtained from a Javanese fig tree
the main protein of the keratohyalin granules
any material that fills a space or container
used for filling cracks or holes in a surface
filter paper
a porous unsized paper used for filtering
the product of filtration; a gas or liquid that has been passed through a filter
once thought to be one of four elements composing the universe (Empedocles)
fuel that is burning and is used as a means for cooking
fire opal
an opal with flaming orange and yellow and red colors
a heat-resistant clay
a mixture of gases (mostly methane) that form in coal mines and become explosive when mixed with air
(a piece of) a substance that burns easily and can be used to start a coal or coke fire
a piece of flint that is struck to light a fire
wood used for fuel
fish glue
gelatinous substance obtained by boiling skins fins and bones of fish
fish meal
ground dried fish used as fertilizer and as feed for domestic livestock
fish oil
a fatty oil obtained from the livers of various fish
a compound (such as ethanol or formaldehyde) that fixes tissues and cells for microscopic study
a chemical compound that sets or fixes something (as a dye or a photographic image)
a ketone that forms the nucleus of certain natural yellow pigments like riboflavin
a colorless crystalline compound that is part of a number of white or yellow plant pigments
any of a large class of plant pigments having a chemical structure based on or similar to flavone
fiber of the flax plant that is made into thread and woven into linen fabric
neuromuscular blocking agent (trade name Flaxedil) used as a muscle relaxant in the administration of anesthesia
flaxseed oil
a drying oil extracted from flax seed and used in making such things as oil paints
the seed of flax used as a source of oil
the wool of a sheep or similar animal
tanned skin of a sheep with the fleece left on; used for clothing
a thin strong lightweight translucent paper used especially for making carbon copies
a hard kind of stone; a form of silica more opaque than chalcedony
flint glass
optical glass of high dispersion and high refractive index
pebbles of flint used in masonry construction
a small loosely aggregated mass of flocculent material suspended in or precipitated from a liquid
floor wax
a preparation containing wax and used to polish and preserve the finish of floors
building material used in laying floors
flowers of zinc
oxide of zinc; a white powder used as a pigment or in cosmetics or glass or inks and in zinc ointment
any light downy material
a substance that is fluid at room temperature and pressure
continuous amorphous matter that tends to flow and to conform to the outline of its container: a liquid or a gas
a soft mineral (calcium fluoride) that is fluorescent in ultraviolet light; chief source of fluorine
a form of apatite in which fluorine predominates over chlorine
fluorescein isocyanate
a fluorochrome commonly conjugated with antibodies for use in indirect immunofluorescence
a yellow dye that is visible even when highly diluted; used as an absorption indicator when silver nitrate solution is added to sodium chloride in order to precipitate silver chloride (turns pink when no chloride ions are left in solution and negative fluorescein ions are then absorbed)
a salt of hydrofluoric acid
fluoroboric acid
an acid of fluorine and boron
a salt of fluoroboric acid
a halocarbon in which some hydrogen atoms have been replaced by fluorine; used in refrigerators and aerosols
fluorocarbon plastic
a plastic made with fluorocarbon
any of various fluorescent substances used in fluorescence microscopy to stain specimens
colorless gas haloform CHF3 (similar to chloroform)
salt of fluosilicic acid
fluosilicic acid
an unstable poisonous corrosive acid known primarily in the form of its salts
a substance added to molten metals to bond with impurities that can then be readily removed
fly ash
fine solid particles of ash that are carried into the air when fuel is combusted
paper that is poisoned or coated with a sticky substance to kill flies
a tiny dark speck made by the excrement of a fly
a radioactive transuranic metallic element produced by bombarding plutonium with neutrons
a lightweight material in cellular form; made by introducing gas bubbles during manufacture
foam rubber
spongy rubber; made by introducing air bubbles before vulcanization and used for cushioning or upholstery
a substance used as a warm moist medicinal compress or poultice
food waste
food that is discarded (as from a kitchen)
fool's gold
a common mineral (iron disulfide) that has a pale yellow color
a colorless poisonous gas; made by the oxidation of methanol
a 10% solution of formaldehyde in water; used as a disinfectant or to preserve biological specimens
formic acid
a colorless pungent fuming vesicatory liquid acid HCOOH found naturally in ants and many plants or made catalytically from carbon monoxide and steam; used in finishing textiles and paper and in the manufacture of insecticides and fumigants
a substance prepared according to a formula
Forssman antibody
an antibody found in the blood of someone suffering from infectious mononucleosis
(chemistry) the negative univalent acyl radical CHO that occurs in aldehydes
fossil fuel
fuel consisting of the remains of organisms preserved in rocks in the earth's crust with high carbon and hydrogen content
the grey or reddish-brown fur of a fox
a radioactive element of the alkali-metal group discovered as a disintegration product of actinium
a component of a mixture that has been separated by a fractional process
an aromatic gum resin obtained from various Arabian or East African trees; formerly valued for worship and for embalming and fumigation
free radical
an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule
freezing mixture
a mixture of substances (usually salt and ice) to obtain a temperature below the freezing point of water
French chalk
a soft white compact talc used to mark cloth or to remove grease stains
French ultramarine blue
ultramarine pigment prepared artificially
any one or more chlorofluorocarbons (or related compounds) that are used as an aerosol propellant, organic solvent, or refrigerant
fresh water
water that is not salty
ice crystals forming a white deposit (especially on objects outside)
a simple sugar found in honey and in many ripe fruits
a gonadotropic hormone that is secreted by the anterior pituitary and stimulates growth of Graafian follicles in female mammals, and activates the cells in male mammals that form sperm
a substance that can be consumed to produce energy
fuel oil
a petroleum product used for fuel
fuller's earth
an absorbent soil resembling clay; used in fulling (shrinking and thickening) woolen cloth and as an adsorbent
a form of carbon having a large molecule consisting of an empty cage of sixty or more carbon atoms
a salt or ester of fulminic acid
fulminate of mercury
a fulminate that when dry explodes violently if struck or heated; used in detonators and blasting caps and percussion caps
fulminic acid
(CNOH) an unstable acid occurring mainly in the form of explosive salts and esters that is isomeric with cyanic acid
fulvic acid
a yellow to yellow-brown humic substance that is soluble in water under all pH conditions
fumaric acid
a colorless crystalline acid with a fruity taste; used in making polyester resins
a chemical substance used in fumigation
the dressed hairy coat of a mammal
a colorless toxic flammable liquid used in the synthesis of nylon
a liquid aldehyde with a penetrating odor; made from plant hulls and corncobs; used in making furan and as a solvent
fusel oil
a mixture of amyl alcohols and propanol and butanol formed from distillation of fermented liquors
fusible metal
an alloy with a low melting point and used as solder and in safety plugs and sprinkler fuses
a purine base found in DNA and RNA; pairs with cytosine
one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
a rare silvery (usually trivalent) metallic element; brittle at low temperatures but liquid above room temperature; occurs in trace amounts in bauxite and zinc ores
the first known nerve agent, synthesized by German chemists in 1936; a highly toxic combustible liquid that is soluble in organic solvents and is used as a nerve gas in chemical warfare
an amino acid that is found in the central nervous system; acts as an inhibitory neurotransmitter
one of a family of granular intrusive rocks
a mineral that is a source of rare earths; consists of silicates of iron and beryllium and cerium and yttrium and erbium
agent that induces milk secretion
a bitter aromatic gum resin that resembles asafetida
soft blue-grey mineral; lead sulfide; a major source of lead
gallic acid
a colorless crystalline acid obtained from tannin
galvanized iron
iron that is coated with zinc to protect it from rust
a gum resin used as a yellow pigment and a purgative
gamma acid
a crystalline acid used to make azo dyes
gamma globulin
a plasma protein containing the immunoglobulins that are responsible for immune responses
gamma iron
a nonmagnetic allotrope of iron that is the basis of austenite; stable between 906 and 1403 degrees centigrade
a medicated solution used for gargling and rinsing the mouth
any of a group of hard glassy minerals (silicates of various metals) used as gemstones and as an abrasive
garnet lac
lac refined by treating with solvent; garnet-colored
a green mineral consisting of hydrated nickel magnesium silicate; a source of nickel
a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely
gas oil
an oil formed through distillation of petroleum of intermediate boiling range and viscosity
a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines
a fossil fuel in the gaseous state; used for cooking and heating homes
a gasoline substitute consisting of 90% gasoline and 10% grain alcohol from corn
a highly toxic chemical nerve agent that inhibits the activity of cholinesterase
a ductile silvery-white ductile ferromagnetic trivalent metallic element of the rare earth group
a nerve agent easily absorbed into the body; a lethal cholinesterase inhibitor that is highly toxic when inhaled
a brittle grey crystalline element that is a semiconducting metalloid (resembling silicon) used in transistors; occurs in germanite and argyrodite
a colorless water-soluble glutinous protein obtained from animal tissues such as bone and skin
a crystalline rock that can be cut and polished for jewelry
German silver
a silver-white alloy containing copper and zinc and nickel
a rare reddish-grey mineral consisting of a copper iron germanium sulfide
gypsum or plaster of Paris spread on a surface to make it suitable for painting or gilding (or a surface so prepared)
an Indian gum from the dhawa tree; used as a substitute for gum arabic
Ghedda wax
wax from Indian and African bees
a releasing factor that accelerates the secretion of growth hormone by the anterior pituitary body
gibberellic acid
a crystalline acid associated with gibberellin
a plant hormone isolated from a fungus; used in promoting plant growth
white crystalline mineral consisting of aluminum hydroxide; a constituent of bauxite and a source of alumina
gift wrap
attractive wrapping paper suitable for wrapping gifts
gilding metal
a brass that is rich in copper; used to make articles that were to be gilded
gilgai soil
soil in the melon holes of Australia
derived from ginger; source of the hotness of ginger
a brittle transparent solid with irregular atomic structure
glass wool
glass fibers spun and massed into bundles resembling wool
Glauber's salts
(Na2SO4.10H2O) a colorless salt used as a cathartic
a green mineral consisting of hydrated silicate of potassium or iron or magnesium or aluminum; found in greensand
a colorless protein obtained by removing heme from hemoglobin; the oxygen carrying compound in red blood cells
globular pearlite
if steel or iron cool very slowly the cementite may occur in globules instead of in layers
a family of proteins found in blood and milk and muscle and in plant seed
any gummy shapeless matter; usually unpleasant
glove leather
leather suitable for making gloves
a steroid hormone that is produced by the adrenal cortex of animals; affects functioning of gonads and has anti-inflammatory activity
an amino derivative of glucose that is a component of many polysaccharides
a monosaccharide sugar that has several forms; an important source of physiological energy
a glycoside derived from glucose
cement consisting of a sticky substance that is used as an adhesive
a salt or ester of glutamic acid
glutamic acid
an amino acid occurring in proteins; important in the nitrogen metabolism of plants; used in monosodium glutamate to enhance the flavor of meats
glutamic oxalacetic transaminase
an enzyme involved in transamination
a crystalline amino acid occurring in proteins; important in protein metabolism
glutathione peroxidase
an enzyme in the body that is a powerful scavenger of free radicals
a simple protein found in the seeds of cereals
a sweet crystalline aldehyde formed by the breakdown of sugars
glyceric acid
a syrupy acid obtained by oxidation of glycerol or glyceraldehyde
glycerin jelly
a mixture of glycerin and gelatin that is used in histology for mounting specimens
a sweet syrupy trihydroxy alcohol obtained by saponification of fats and oils
glycerinated gelatin
a gelatinous preparation made from gelatin and glycerin and water; used as a base for ointments and suppositories
a medicine made by mixing a substance in glycerin
a medicated skin preparation made from glycerin and glycerinated gelatin
glycerol trimargarate
a glyceryl ester of margaric acid
glycerol tripalmitate
a triglyceride of palmitic acid
glycerol tristearate
a triglyceride of stearic acid
a trivalent radical derived from glycerol by removing the three hydroxyl radicals
glyceryl ester
an ester of glycerol
the simplest amino acid found in proteins and the principal amino acid in sugar cane
glycolic acid
a translucent crystalline compound found in sugar cane and sugar beets and unripe grapes
a conjugated protein having a carbohydrate component
a group of compounds derived from monosaccharides
an organic base C3H4N2; a histamine inhibitor
a laminated metamorphic rock similar to granite
the hide of a goat
a red or yellow or brown mineral; an oxide of iron that is a common constituent of rust
any substance (such as thiouracil) that induces the formation of a goiter
gold dust
the particles and flakes (and sometimes small nuggets) of gold obtained in placer mining
Golden Fleece
in Greek mythology, a fleece of gold owned by the king of Colchis and guarded in a sacred grove by a dragon; recovered by Jason and the Argonauts
aventurine spangled densely with fine gold-colored particles
any thick, viscous matter
goose grease
grease derived from geese
the side of leather from which the hair has been removed
Gram's solution
a solution used in staining bacteria by Gram's method; consists of one part iodine and two parts potassium iodide and 300 parts water
plutonic igneous rock having visibly crystalline texture; generally composed of feldspar and mica and quartz
graph paper
paper that has lines to permit drawing graphs
graphic tellurium
a silver-white mineral consisting of silver gold telluride; a source of gold in Australia and America
a thick fatty oil (especially one used to lubricate machinery)
greaseproof paper
paper that is impermeable to oil or grease; used in cooking
Greek fire
a mixture used by Byzantine Greeks that was often shot at adversaries; catches fire when wetted
green gold
a gold alloy (at least 14 karat gold with silver or silver and cadmium) that has a green appearance
green lead ore
a mineral consisting of lead chloride and phosphate; a minor source of lead
green manure
a growing crop that is plowed under to enrich soil
greenhouse emission
a gas that contributes to the greenhouse effect by absorbing infrared radiation
Greenland spar
a white mineral consisting of fluorides of aluminum and sodium; a source of fluorine
an olive-green sandstone containing glauconite
a granitic rock composed of quartz and mica
grid metal
a kind of hard lead that is used for grids in storage batteries
a hard coarse-grained siliceous sandstone
ground glass
glass that diffuses light due to a rough surface produced by abrasion or etching
ground glass
particulate glass made by grinding and used as an abrasive
ground water
underground water that is held in the soil and in pervious rocks
(geology) the matrix of fine-grained crystalline material in which larger crystals are embedded
a thin mortar that can be poured and used to fill cracks in masonry or brickwork
growth factor
a protein that is involved in cell differentiation and growth
growth regulator
(botany) a plant product that acts like a hormone
a thick viscous liquid
the excrement of sea birds; used as fertilizer
guar gum
a gum from seeds of the guar plant; used to thicken foods and as sizing for paper and cloth
guinea gold
22-karat gold from which guinea coins were made
guinea gold
brass with enough copper to give it a reddish tint; used for plumbing pipe and other brass hardware and in cheap jewelry
any of various substances (soluble in water) that exude from certain plants; they are gelatinous when moist but harden on drying
gum acacia
gum from an acacia tree; used as a thickener (especially in candies and pharmaceuticals)
gum kino
a gum obtained from various tropical plants; used as an astringent and in tanning
gum labdanum
a dark brown to greenish oleoresin that has a fragrant odor and is used as a fixative in perfumes; obtained as a juice from certain rockroses
gum resin
a mixture of resin and gum
gum sangapenum
a variety of gum
gum terpentine
obtained from conifers (especially pines)
an inferior lac produced by lac insects in Madagascar
any of various fine-grained silty soils that become waxy and very sticky mud when saturated with water
a gummy orange mixture of uranium oxides and silicates occurring naturally in the hydration and oxidation of pitchblende
a mixture of cement and sand and water that is sprayed on a surface under pneumatic pressure
a type of bronze used for parts subject to wear or corrosion (especially corrosion by sea water)
a mixture of potassium nitrate, charcoal, and sulfur in a 75:15:10 ratio which is used in gunnery, time fuses, and fireworks
a whitish rubber derived from the coagulated milky latex of gutta-percha trees; used for insulation of electrical cables
a common white or colorless mineral (hydrated calcium sulphate) used to make cements and plasters (especially plaster of Paris)
a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe
binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent
a complex red organic pigment containing iron and other atoms to which oxygen binds
the principal form of iron ore; consists of ferric oxide in crystalline form; occurs in a red earthy form
a conjugated protein linked to a compound of iron and porphyrin
a granular brown substance composed of ferric oxide; left from the breakdown of hemoglobin; can be a sign of disturbed iron metabolism
Hageman factor
coagulation factor whose deficiency results in prolongation of clotting time of venous blood
small pellet of ice that falls during a hailstorm
hair coloring
a dye for coloring the hair
halibut-liver oil
a fatty oil from halibut livers that is used as a source of vitamin A
a salt of any halogen acid
naturally occurring crystalline sodium chloride
offensive breath
one of various compounds of carbon and any of the halogens
compounds with the formula CHX3, where X is a halogen atom
any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions
a compound in which the hydrogen atoms of a hydrocarbon have been replaced by bromine and other halogen atoms; very stable; used in fire extinguishers although it is thought to release bromine that depletes the ozone layer
hanging chad
a chad that is incompletely removed and hanging by one corner
a protein in plasma that binds free hemoglobin and removes it (as from wounds)
hard lead
unrefined lead that is hard because of the impurities it contains
hard solder
solder that contains copper; melts at a relatively high temperature; used for brazing
hard steel
steel with more than 0.3% carbon
hard water
water that contains mineral salts (as calcium and magnesium ions) that limit the formation of lather with soap
a mountain mahogany
the wood of broad-leaved dicotyledonous trees (as distinguished from the wood of conifers)
harlequin opal
a reddish opal with small patches of brilliant color
a mineral consisting of manganese tetroxide; a source of manganese
an abbreviation for `hazardous material' used on warning signs
a hemoprotein composed of globin and heme that gives red blood cells their characteristic color; function primarily to transport oxygen from the lungs to the body tissues
a fluorocarbon that is replacing chlorofluorocarbon as a refrigerant and propellant in aerosol cans; considered to be somewhat less destructive to the atmosphere
hormone produced early in pregnancy by the placenta; detection in the urine and serum is the basis for one kind of pregnancy test
a lipoprotein that transports cholesterol in the blood; composed of a high proportion of protein and relatively little cholesterol; high levels are thought to be associated with decreased risk of coronary heart disease and atherosclerosis
HDL cholesterol
the cholesterol in high-density lipoproteins; the `good' cholesterol; a high level in the blood is thought to lower the risk of coronary artery disease
a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
heavy metal
a metal of relatively high density (specific gravity greater than about 5) or of high relative atomic weight (especially one that is poisonous like mercury or lead)
helium group
the series of inert gases
a reddish coloring material found in some algae
an organic compound usually formed as an intermediate product in the preparation of acetals from aldehydes or ketones
a reddish-brown chloride of heme; produced from hemoglobin in laboratory tests for the presence of blood
poisonous drug derived from an Eurasian plant of the genus Conium
a plant fiber
a reddish brown dye used especially on hair
any toxin that affects the liver
heptadecanoic acid
a colorless crystalline synthetic fatty acid
a colorless volatile highly flammable liquid obtained from petroleum and used as an anesthetic or a solvent or in determining octane ratings
a chemical agent that destroys plants or inhibits their growth
a compound containing a heterocyclic ring
a group of minerals of the zeolite family consisting of a hydrous aluminum silicate of sodium and calcium
hexadecanoic acid
a saturated fatty acid that is the major fat in meat and dairy products
a colorless flammable liquid alkane derived from petroleum and used as a solvent
estrogen compound used to treat menstrual irregularities and menopausal symptoms and to prevent pregnancy
a monosaccharide that contains six carbon atoms per molecule
a grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons
a fluorocarbon emitted as a by-product of industrial manufacturing
a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures
a green transparent form of the mineral spodumene used as a gemstone
high brass
brass with 35% zinc
high explosive
a powerful chemical explosive that produces gas at a very high rate
high-level radioactive waste
radioactive waste that left in a nuclear reactor after the nuclear fuel has been consumed
high-speed steel
an alloy steel that remains hard at a red heat; used to make metal-cutting tools
high-strength brass
a brass with from 1-4% manganese to harden it
hip tile
a tile shaped so as to cover the hip of a hip roof
enzyme that acts as a catalyst in converting histidine to histamine
an essential amino acid found in proteins that is important for the growth and repair of tissue
a simple protein containing mainly basic amino acids; present in cell nuclei in association with nucleic acids
a colorless explosive liquid that is volatile and poisonous and foul-smelling
a trivalent metallic element of the rare earth group; occurs together with yttrium; forms highly magnetic compounds
holy water
water that has been blessed by a priest for use in symbolic purification
material that has been homogenized (especially tissue that has been ground and mixed)
Hooker's green
green pigment consisting of Prussian blue mixed with gamboge
the material (mostly keratin) that covers the horns of ungulates and forms hooves and claws and nails
a green to black mineral of the amphibole group; consists of silicates of calcium and sodium and magnesium and iron
a fine-grained metamorphic rock formed by the action of heat on clay rocks
horse manure
horse excreta used as fertilizer
hair taken from the mane or tail of a horse
leather from the hide of a horse
horseradish peroxidase
an enzyme used in immunohistochemistry to label antigens and their antibodies
hot air
air that has been heated and tends to rise
a radioactive transuranic element
hudson seal
muskrat fur dressed to simulate sealskin
human waste
the body wastes of human beings
material that is high in humic acids
any substance that is added to another substance to keep it moist
humic acid
a dark brown humic substance that is soluble in water only at pH values greater than 2
humic shale
shale that is rich in humic acids
humic substance
an organic residue of decaying organic matter
a black humic substance that is not soluble in water
partially decomposed organic matter; the organic component of soil
a red transparent variety of zircon used as a gemstone
a glassy translucent substance that occurs in hyaline cartilage or in certain skin conditions
hyaluronic acid
a viscous mucopolysaccharide found in the connective tissue space and the synovial fluid of movable joints and the humors of the eye; a cementing and protective substance
an enzyme (trade name Hyazyme) that splits hyaluronic acid and so lowers its viscosity and increases the permeability of connective tissue and the absorption of fluids
any compound that contains water of crystallization
hydrated oxide
a compound of an oxide with water
a colorless fuming corrosive liquid; a powerful reducing agent; used chiefly in rocket fuels
hydrazo group
the bivalent group -HNNH- derived from hydrazine
a salt of hydrazoic acid
any binary compound formed by the union of hydrogen and other elements
hydriodic acid
(HI) a colorless or yellow aqueous solution of hydrogen iodide
hydrobromic acid
an aqueous solution of hydrogen bromide that is a strong liquid acid
an organic compound containing only carbon and hydrogen
a complex consisting of an organic base in association with hydrogen chloride
a substance that forms a gel with water
an adrenal-cortex hormone (trade names Hydrocortone or Cortef) that is active in carbohydrate and protein metabolism
hydrocyanic acid
a solution of hydrogen cyanide in water; weak solutions are used in fumigating and in the synthesis of organic compounds
hydrofluoric acid
a weak poisonous liquid acid; formed by solution of hydrogen fluoride in water
a colloidal gel in which water is the dispersion medium
hydrogen atom
an atom of hydrogen
hydrogen bromide
a colorless gas that yields hydrobromic acid in solution with water
hydrogen chloride
a colorless corrosive gas (HCl)
hydrogen cyanide
a highly poisonous gas or volatile liquid that smells like bitter almonds; becomes a gas at around 90 degree Fahrenheit and is most dangerous when inhaled; the anhydride of hydrocyanic acid; used in manufacturing
hydrogen fluoride
a colorless poisonous corrosive liquid made by the action of sulphuric acid on calcium fluoride; solutions in water are hydrofluoric acid
hydrogen iodide
a colorless gas that yields hydroiodic acid in aqueous solution
hydrogen peroxide
a viscous liquid with strong oxidizing properties; a powerful bleaching agent; also used (in aqueous solutions) as a mild disinfectant and (in strong concentrations) as an oxidant in rocket fuels
hydrogen sulfide
a sulfide having the unpleasant smell of rotten eggs
hydroiodic acid
an acid formed by aqueous solution of hydrogen iodide
a product of hydrolysis
a chemical compound containing the hydroxyl group
hydroxide ion
the anion OH having one oxygen and one hydrogen atom
hydroxy acid
any acid that has hydroxyl groups in addition to the hydroxyl group in the acid itself
hydroxybenzoic acid
a crystalline derivative of benzoic acid
hydroxybutyric acid
hydroxy derivative of butyric acid
the monovalent group -OH in such compounds as bases and some acids and alcohols
a methyl with hydroxide replacing the hydrogen atoms
a crystalline amino acid obtained from gelatin or collagen
hyper-eutectoid steel
a steel that contains more than 0.9% carbon
an agent that induces drowsiness or sleep
a compound used as a fixing agent in photographic developing
hypo-eutectoid steel
a steel that contains less that 0.9% carbon
any salt or ester of hypochlorous acid
hypochlorous acid
a weak unstable acid known only in solution and in its salts; used as a bleaching agent and as an oxidizing agent
hypoglycaemic agent
any of various agents that decrease the level of glucose in the blood and are used in the treatment of diabetes mellitus
hyponitrous acid
an explosive white crystalline weak acid (H2N2O2)
hypophosphoric acid
a crystalline tetrabasic acid (H4P2O6)
hypophosphorous acid
a clear or yellow monobasic acid (H3PO2)
a nonmetallic element belonging to the halogens; used especially in medicine and photography and in dyes; occurs naturally only in combination in small quantities (as in sea water or rocks)
a plant hormone promoting elongation of stems and roots
water frozen in the solid state
Iceland spar
a transparent calcite found in Iceland and used in polarizing microscopes
(Greek mythology) the rarified fluid said to flow in the veins of the Gods
ice resembling a pendent spear, formed by the freezing of dripping water
a gonadotropic hormone that is secreted by the anterior pituitary; stimulates ovulation in female mammals and stimulates androgen release in male mammals
ideal gas
a hypothetical gas with molecules of negligible size that exert no intermolecular forces
identification particle
a tiny particle of material that can be added to a product to indicate the source of manufacture
a green or yellow or brown mineral consisting of a hydrated silicate; it occurs as crystals in limestone and is used a gemstone
a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response
igneous rock
rock formed by the solidification of molten magma
a substance used to ignite or kindle a fire
something that can serve as a source of light
a weakly magnetic black mineral found in metamorphic and plutonic rocks; an iron titanium oxide in crystalline form; a source of titanium
any of a class of organic compounds that contain the divalent radical -CONHCO-
immunoglobulin A
one of the most common of the five major classes of immunoglobulins; the chief antibody in the membranes of the gastrointestinal and respiratory tracts
immunoglobulin D
one of the five major classes of immunoglobulins; present in blood serum in small amounts
immunoglobulin E
one of the five major classes of immunoglobulins; present primarily in the skin and mucous membranes
immunoglobulin G
one of the five major classes of immunoglobulins; the main antibody defense against bacteria
immunoglobulin M
one of the five major classes of immunoglobulins; involved in fighting blood infections and in triggering production of immunoglobulin G
material with which something is impregnated
a rare soft silvery metallic element; occurs in small quantities in sphalerite
a substance that produces a fragrant odor when burned
a nickel-base alloy with chromium and iron; used in gas-turbine blades
indelible ink
ink that cannot be erased or washed away
a colorless liquid hydrocarbon extracted from petroleum or coal tar and used in making synthetic resins
India ink
a black liquid ink used for printing or writing or drawing
india paper
a thin tough opaque paper used in fine books
India rubber
an elastic material obtained from the latex sap of trees (especially trees of the genera Hevea and Ficus) that can be vulcanized and finished into a variety of products
Indian red
a red soil containing ferric oxide; often used as a pigment
Indian red
a red pigment composed in part from ferric oxide which is often used in paints and cosmetics
(chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction
indolebutyric acid
a synthetic plant hormone promoting elongation of stems and roots
an agent capable of activating specific genes
indurated clay
hardened clay
informational RNA
the template for protein synthesis; the form of RNA that carries information from DNA in the nucleus to the ribosome sites of protein synthesis in the cell
ingot iron
iron of high purity
something that is inhaled
a substance that retards or stops an activity
any solution that is injected (as into the skin)
a liquid used for printing or writing or drawing
a substance (a virus or toxin or immune serum) that is introduced into the body to produce or increase immunity to a particular disease
inorganic compound
any compound that does not contain carbon
inorganic phosphate
a salt of phosphoric acid
a nucleoside that is formed by the deamination of adenosine; used in kidney transplantation to provide a temporary source of sugar
an optically inactive alcohol that is a component of the vitamin B complex
insect powder
a chemical used to kill insects
insect repellant
a chemical substance that repels insects
a liquid that is instilled drop by drop
insulating material that reduces or prevents the transmission of heat or sound or electricity
any of several lymphokines that promote macrophages and killer T cells and B cells and other components of the immune system
a substance formed during a chemical process before the desired product is obtained
intrinsic factor
a substance produced by the mucosa of the stomach and intestines that is essential for the absorption of vitamin B12
a monoamine neurotransmitter found in the brain and essential for the normal functioning of the central nervous system; as a drug (trade names Dopastat and Intropin) it is used to treat shock and hypotension
used to manufacture fructose and in assessing kidney function
an alloy of iron and nickel having a low coefficient of thermal expansion; used in tuning forks and measuring tapes and other instruments
invert sugar
a mixture of equal parts of glucose and fructose resulting from the hydrolysis of sucrose; found naturally in fruits; sweeter than glucose
an enzyme that catalyzes the hydrolysis of sucrose into glucose and fructose
iodic acid
a soluble crystalline acid; used as a reagent and disinfectant
a salt or ester of hydriodic acid
iodinated protein
a protein that contains iodine
light radioactive isotope of iodine with a half-life of 60 days; used as a tracer in thyroid studies and as a treatment for hyperthyroidism
heavy radioactive isotope of iodine with a half-life of 8 days; used in a sodium salt to diagnose thyroid disease and to treat goiter
iodoamino acid
an amino acid with iodine added
a compound containing the covalent iodine radical
sweet smelling yellow solid haloform CHI3
a violet photopigment in the retinal cones of the eyes of most vertebrates; plays a role in daylight vision
thyronine with iodine added
tyrosine with iodine added
a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium
a hard and corrosion resistant mineral that is a natural alloy of osmium and iridium (usually containing small amounts of rhodium and platinum); used in needles and pen nibs etc.
iron disulfide
a compound containing two atoms of sulfur combined with iron
iron manganese tungsten
a mineral consisting of iron and manganese tungstate in crystalline form; the principal ore of tungsten; found in quartz veins associated with granitic rocks
iron ore
an ore from which iron can be extracted
iron perchloride
a highly toxic chemical used to engrave metal plates and electronic circuits
iron putty
a cement resembling putty; made by mixing ferric oxide and boiled linseed oil; is acid resistant
any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity
an antibody produced by one individual that causes agglutination of red blood cells in other individuals of the same species
an antigen capable of causing the production of (or reacting with) an isoagglutinin
used also in making gasoline components
a salt or ester of isocyanic acid
isocyanic acid
an acid known only in the form of its esters
an essential amino acid found in proteins; isomeric with leucine
a compound that exists in forms having different arrangements of atoms but the same molecular weight
an enzyme that catalyzes its substrate to an isomeric form
alcohol used as antifreeze or a solvent
isosmotic solution
a solution having the same osmotic pressure as blood
a family of compounds derived from horseradish and radishes and onions and mustards; source of the hotness of those plants and preparations
one of two or more atoms with the same atomic number but with different numbers of neutrons
itaconic acid
a crystalline carboxylic acid; occurs in some fermentations of sugars
ivory black
a black pigment made from grinding burnt ivory in oil
a hard smooth ivory colored dentine that makes up most of the tusks of elephants and walruses
a semiprecious gemstone that takes a high polish; is usually green but sometimes whitish; consists of jadeite or nephrite
a hard green mineral consisting of sodium aluminum silicate in monoclinic crystalline form; a source of jade; found principally in Burma
unrefined brown sugar made from palm sap
Japan tallow
a yellow wax obtained from sumac berries; used in polishes
a colorless (or pale yellow or smoky) variety of zircon
an opaque form of quartz; red or yellow or brown or dark green in color; used for ornamentation or as a gemstone
any substance having the consistency of jelly or gelatin
a hard black form of lignite that takes a brilliant polish and is used in jewelry or ornamentation
joss stick
a slender stick of incense burned before a joss by the Chinese
jumping gene
a segment of DNA that can become integrated at many different sites along a chromosome (especially a segment of bacterial DNA that can be translocated as a whole)
juniperic acid
a crystalline acid found in the exudations of some conifers
junk DNA
stretches of DNA that do not code for genes
a plant fiber used in making rope or sacks
a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite
K-Dur 20
salt of potassium (KCl) (trade names K-Dur 20, Kaochlor and K-lor and Klorvess and K-lyte); taken in tablet form to treat potassium deficiency
a white mineral consisting of magnesium sulphate and potassium chloride; a source of potassium salts; used as a fertilizer
a mineral consisting of aluminum silicate; main source of kaolin
a plant fiber from the kapok tree; used for stuffing and insulation
karaya gum
exudate of an Asian tree; used for finishing textiles and to thicken foodstuffs and cosmetics
resin of the kauri trees of New Zealand; found usually as a fossil; also collected for making varnishes and linoleum
Kekule formula
a closed chain of 6 carbon atoms with hydrogen atoms attached
Kendal green
a green dye, often used to color cloth, which is obtained from the woad plant
hyaline in the large granules of the stratum granulosum
a light soft mineral consisting of hydrated sodium borate in crystalline form; an important source of boron
a monosaccharide having six carbon atoms and a ketone group
any of a class of organic compounds having a carbonyl group linked to a carbon atom in each of two hydrocarbon radicals
ketone group
a group having the characteristic properties of ketones
any monosaccharide sugar that contains a ketone group or its hemiacetal
a steroid containing a ketone group
soft smooth leather from the hide of a young goat
a white mineral consisting of hydrous magnesium sulfate often found in salt mines
a rare type of peridotite that sometimes contains diamonds; found in South Africa and Siberia
an enzyme that catalyzes the conversion of a proenzyme to an active enzyme
material for starting a fire
Kitty Litter
granulated clay; placed in a container where it absorbs the waste products of a cat or dog
a piece of soft absorbent paper (usually two or more thin layers) used as a disposable handkerchief
a hard cross-grained round piece of wood in a board where a branch emerged
a hole in a board where a knot came out
kokoi venom
a potent neurotoxin found in a particular frog
a colorless element that is one of the six inert gasses; occurs in trace amounts in air
strong wrapping paper made from pulp processed with a sulfur solution
a pinkish lilac crystal form of the mineral spodumene that is used as a gemstone
a preparation of lindane (trade name Kwell) that is used to kill lice and itch mites; available in cream or shampoo
a white soft metallic element that tarnishes readily; occurs in rare earth minerals and is usually classified as a rare earth
a radioactive isotope that is used in a compound in order to trace the mechanism of a chemical reaction
resinlike substance secreted by certain lac insects; used in e.g. varnishes and sealing wax
lac dye
scarlet dye like cochineal; extracted with alkali from stick lac
lac wax
a hard wax separated from shellac by its insolubility in alcohol
a gas that makes the eyes fill with tears but does not damage them; used in dispersing crowds
a black resinous substance obtained from certain trees and used as a natural varnish
any of a group of enzymes (trade name Lactaid) that hydrolyze lactose to glucose and galactose
albumin occurring in milk
a salt or ester of lactic acid
lactic acid
a clear odorless hygroscopic syrupy carboxylic acid found in sour milk and in many fruits
any agent that reduces milk secretion (as given to a woman who is not breast feeding)
any agent that enhances milk production
lactogenic hormone
gonadotropic hormone secreted by the anterior pituitary; in females it stimulates growth of the mammary glands and lactation after parturition
a sugar comprising one glucose molecule linked to a galactose molecule; occurs only in milk
a substance derived from amygdalin; publicized as an antineoplastic drug although there is no supporting evidence
insulation used to wrap around pipes or boilers or laid in attics to prevent loss of heat
laid paper
writing paper having a watermark of fine lines running across the grain
any of numerous bright translucent organic pigments
a purplish red pigment prepared from lac or cochineal
the skin of a lamb with the wool still on
skin of a sheep or goat prepared for writing on
lamellar mixture
a mixture in which substances occur in distinct layers
laminated glass
glass made with plates of plastic or resin or other material between two sheets of glass to prevent shattering
a mineral consisting of potassium magnesium double sulphate; used as a fertilizer
a yellow viscous animal oil extracted from wool; a mixture of fatty acids and esters; used in some ointments and cosmetics
lanthanide series
the rare-earth elements with atomic numbers 57 through 71; having properties similar to lanthanum
any element of the lanthanide series (atomic numbers 57 through 71)
the fur of a rabbit
lapis lazuli
an azure blue semiprecious stone
lard oil
oil consisting chiefly of olein that is expressed from lard and used especially as a lubricant, cutting oil or illuminant
an insecticide that kills the larvae of insects
a chemical used to kill larval pests
aromatic Turkish tobacco
a red soil produced by rock decay; contains insoluble deposits of ferric and aluminum oxides
a milky exudate from certain plants that coagulates on exposure to air
lath and plaster
a building material consisting of thin strips of wood that provide a foundation for a coat of plaster
brass (or a yellow alloy resembling brass) that was hammered into thin sheets; formerly used for church utensils
rock that in its molten form (as magma) issues from volcanos; lava is what magma is called when it reaches the surface
a lipoprotein that transports cholesterol in the blood; composed of moderate amount of protein and a large amount of cholesterol; high levels are thought to be associated with increased risk of coronary heart disease and atherosclerosis
LDL cholesterol
the cholesterol in low-density lipoproteins; the `bad' cholesterol; a high level in the blood is thought to be related to various pathogenic conditions
lead acetate
a poisonous white solid (Pb[CH3CO]2) used in dyeing cotton and in making enamels and varnishes
lead arsenate
a poisonous white solid (Pb3[AsO4]2) used as an insecticide
lead chromate
a poisonous chromate of lead used as a pigment in paint
lead glass
glass containing lead oxide; has a high refractive index
lead ore
ore containing lead
lead tetraethyl
a clear oily poisonous liquid added to gasoline to prevent knocking
leaded bronze
bronze to which 1-4% lead is added
leaded gasoline
gasoline treated with a lead compound to reduce motor knocks
leaf fat
fat lining the abdomen and kidneys in hogs which is used to make lard
leaf mold
soil composed mainly of decaying leaves
an animal skin made smooth and flexible by removing the hair and then tanning
a substance used to produce fermentation in dough or a liquid
a yellow phospholipid essential for the metabolism of fats; found in egg yolk and in many plant and animal cells; used commercially as an emulsifier
any of several plant glycoproteins that act like specific antibodies but are not antibodies in that they are not evoked by an antigenic stimulus
ledger paper
a durable writing paper used in record books and business ledgers
lemon grass
an aromatic oil that smells like lemon and is widely used in Asian cooking and in perfumes and medicines
the pelt of a leopard
a red to reddish brown mineral consisting of iron oxide hydroxide; often found in iron ores together with goethite
a mineral of the mica group; an important source of lithium
a mica that is a biotite containing iron
letter paper
writing paper for use in writing correspondence
a white crystalline amino acid occurring in proteins that is essential for nutrition; obtained by the hydrolysis of most dietary proteins
Levant morocco
a heavy morocco often used in bookbinding
a soft silver-white univalent element of the alkali metal group; the lightest metal known; occurs in several minerals
library paste
an adhesive made from water and flour or starch; used on paper and paperboard
a substance (an atom or molecule or radical or ion) that forms a complex around a central atom
a complex polymer; the chief constituent of wood other than carbohydrates; binds to cellulose fibers to harden and strengthen cell walls of plants
a sedimentary rock consisting mainly of calcium that was deposited by the remains of marine animals
solution of calcium hydroxide in water used as an antacid
a liquid terpene with a lemon odor; found in lemons and oranges and other essential oils
a widely occurring iron oxide ore; a mixture of goethite and hematite and lepidocrocite
a colorless fragrant liquid found in many essential oils
a white crystalline powder used as an agricultural insecticide
a high-quality paper made of linen fibers or with a linen finish
a floor covering
linoleic acid
a liquid polyunsaturated fatty acid abundant in plant fats and oils; a fatty acid essential for nutrition; used to make soap
linolenic acid
a liquid polyunsaturated fatty acid that occurs in some plant oils; an essential fatty acid
fine ravellings of cotton or linen fibers
a herbicide that kills weeds without harming vegetables
an enzyme secreted in the digestive tract that catalyzes the breakdown of fats into individual fatty acids that can be absorbed into the bloodstream
an oily organic compound insoluble in water but soluble in organic solvents; essential structural component of living cells (along with proteins and carbohydrates)
a steroid hormone (trade name Lipo-Lutin) produced in the ovary; prepares and maintains the uterus for pregnancy
a conjugated protein having a lipid component; the principal means for transporting lipids in the blood
fluid matter having no fixed shape but a fixed volume
a substance that is liquid at room temperature and pressure
liquid air
air in a liquid state
liquid bleach
a solution containing bleaching agents; used for laundry
liquid crystal
a liquid exhibiting properties of a crystal that are not shown by ordinary liquids
liquid nitrogen
nitrogen in a liquid state
Liquid Pred
a dehydrogenated analogue of cortisol (trade names Orasone or Deltasone or Liquid Pred or Meticorten); used as an anti-inflammatory drug in the treatment of arthritis and as an immunosuppressant
a liquid substance that is a solution (or emulsion or suspension) used or obtained in an industrial process
lithia water
mineral water containing lithium salts
a white powder (LiCO3) used in manufacturing glass and ceramics and as a drug; the drug (trade names Lithane or Lithonate or Eskalith) is used to treat some forms of depression and manic episodes of manic-depressive disorder
litmus paper
unsized paper treated with litmus for use as an acid-base indicator
a coloring material (obtained from lichens) that turns red in acid solutions and blue in alkaline solutions; used as a very rough acid-base indicator
rubbish carelessly dropped or left about (especially in public places)
live steam
steam coming from a boiler at full pressure
a permanent magnet consisting of magnetite that possess polarity and has the power to attract as well as to be attracted magnetically
a rich soil consisting of a mixture of sand and clay and decaying organic materials
a fine-grained unstratified accumulation of clay and silt deposited by the wind
a segment of the trunk of a tree when stripped of branches
long-staple cotton
cotton with relatively long fibers
low brass
brass with 30% (or less) zinc
low explosive
an explosive with a low rate of combustion
low-carbon steel
steel with less than 0.15% carbon
low-level radioactive waste
(medicine) radioactive waste consisting of objects that have been briefly exposed to radioactivity (as in certain medical tests)
a bluish translucent magnetic liquid obtained by compressing gaseous oxygen and then cooling it below its boiling point; used as an oxidizer in rocket propellants
a radioactive transuranic element synthesized from californium
a trivalent metallic element of the rare earth group; usually occurs in association with yttrium
a substance capable of reducing friction by making surfaces smooth or slippery
pigment occurring in luminescent organisms (as fireflies); emits heatless light when undergoing oxidation
the wood of trees cut and prepared for use as building material
lunar caustic
silver nitrate fused into sticks and formerly used as a caustic
a substance for packing a joint or coating a porous surface to make it impervious to gas or liquid
yellow carotenoid pigments in plants and animal fats and egg yolks
carotenoid that makes tomatoes red; may lower the risk of prostate cancer
a strong solution of sodium or potassium hydroxide
a cytokine secreted by helper T cells in response to stimulation by antigens and that acts on other cells of the immune system (as by activating macrophages)
lysergic acid
a crystalline acid often used in medical research; obtained from ergotic alkaloids
any substance (such as an antibody) or agent that can cause lysis
an essential amino acid found in proteins; occurs especially in gelatin and casein
a clear oily brown solution of cresols in soap; used as an antiseptic and disinfectant
an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria
an antacid
broken stone used in macadamized roadways
any very large complex molecule; found only in plants and animals
a medium for oil-paints; linseed oil mixed with mastic varnish or turpentine
molten rock in the earth's crust
a white solid mineral that occurs naturally as periclase; a source of magnesium
a white mineral consisting of magnesium carbonate; a source of magnesium
magnesium bicarbonate
a bicarbonate that is a major cause of hard water
magnesium carbonate
a very white crystalline salt that occurs naturally as magnesite or as dolomite
magnesium hydroxide
a white crystalline powder used chiefly in medicines
magnesium nitride
a nitride containing nitrogen and magnesium
magnesium sulfate
a salt of magnesium
magnetic ink
an ink that contains particles of a magnetic substance whose presence can be detected by magnetic sensors
magnetic iron-ore
an oxide of iron that is strongly attracted by magnets
magnetic pyrites
a brownish iron sulfide mineral (FeS) having weak magnetic properties
a green or blue mineral used as an ore of copper and for making ornamental objects
a yellow insecticide used as a dust or spray to control garden pests and house flies and mites
a salt or ester of maleic acid; used as a nontricyclic antidepressant drug for psychomotor activation
maleic acid
a colorless crystalline compound found in unripe fruit (such as apples or tomatoes or cherries) and used mainly to make polyester resins
malt sugar
a white crystalline sugar formed during the digestion of starches
a thick black tar intermediate between petroleum and asphalt
man-made fiber
fiber created from natural materials or by chemical processes
a salt of manganic acid containing manganese as its anion
manganese tetroxide
an oxide of manganese found naturally as hausmannite
manganic acid
a dibasic acid (H2MnO4) found only in solution and in manganate salts
a black mineral consisting of basic manganese oxide; a source of manganese
a lightweight paper used with carbon paper to make multiple copies
a strong paper or thin cardboard with a smooth light brown finish made from e.g. Manila hemp
Manilla hemp
a kind of hemp obtained from the abaca plant in the Philippines
any animal or plant material used to fertilize land especially animal excreta usually with litter material
an enzyme that catalyzes the oxidation of many body compounds (e.g., epinephrine and norepinephrine and serotonin)
maple sugar
sugar made from the sap of the sugar maple tree
a hard crystalline metamorphic rock that takes a high polish; used for sculpture and as building material
marine glue
glue that is not water soluble
marking ink
an indelible ink for marking clothes or linens etc.
a loose and crumbling earthy deposit consisting mainly of calcite or dolomite; used as a fertilizer for soils deficient in lime
metamorphic rock with approximately the same composition as marl
marsh gas
methane gas produced when vegetation decomposes in water
a solid solution of carbon in alpha-iron that is formed when steel is cooled so rapidly that the change from austenite to pearlite is suppressed; responsible for the hardness of quenched steel
a mixture of mashed malt grains and hot water; used in brewing
the mineral form of lead monoxide; in the form of yellow powder it is used as a pigment
an aromatic exudate from the mastic tree; used chiefly in varnishes
a pasty cement used as an adhesive or filler
wood suitable for making matchsticks
wood in small pieces or splinters
the tangible substance that goes into the makeup of a physical object
(geology) a mass of fine-grained rock in which fossils, crystals, or gems are embedded
a mixture of sulfides that forms when sulfide metal ores are smelted
mechanical mixture
a mixture whose components can be separated by mechanical means
thick dark green mucoid material that is the first feces of a newborn child
a liquid with which pigment is mixed by a painter
an intervening substance through which something is achieved
(biology) a substance in which specimens are preserved or displayed
medium steel
steel with 0.15-0.3% carbon
a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers
a white clayey mineral
a synthetic progestational compound used to treat endometrial carcinoma
abnormally dark tarry feces containing blood (usually from gastrointestinal bleeding)
melamine resin
a thermosetting resin formed from melamine and an aldehyde; used in molded products, adhesives, and coatings
insoluble pigments that account for the color of e.g. skin and scales and feathers
melted snow or ice
menhaden oil
a fatty oil obtained from the menhaden fish and used in paint and ink and in treating leather
(archaic) a solvent
a crystalline compound that has the cool and minty taste and odor that occurs naturally in peppermint oil; used as a flavoring and in medicine to relieve itching, pain, and nasal congestion
a poisonous or foul smelling gas emitted from the earth
mesquite gum
a gum obtained from mesquite pods; resembles gum arabic
message pad
a pad of paper on which messages can be written
a synthetic form of estrogen used in combination with a progestin in oral contraceptives
any substance involved in metabolism (either as a product of metabolism or as necessary for metabolism)
any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
metallized dye
acid dye in which the negative ion contains a chelated metal atom
metamorphic rock
rock altered by pressure and heat
metaphosphoric acid
a glassy solid acid ([HPO3]n) often used as a dehydrating agent
a colorless odorless gas used as a fuel
a light volatile flammable poisonous liquid alcohol; used as an antifreeze and solvent and fuel and as a denaturant for ethyl alcohol
a crystalline amino acid containing sulfur; found in most proteins and essential for nutrition
methyl bromide
a poisonous gas or liquid (CH3Br) used to fumigate rodents, worms, etc.
methyl orange
an azo dye used as an acid-base indicator; used for titrations involving weak bases
the univalent radical CH3- derived from methane
methylated spirit
ethyl alcohol denatured with methyl alcohol to prevent its use as an alcoholic beverage
a colorless flammable liquid obtained from petroleum or coal tar; used as a solvent for gums and lacquers and in high-octane fuels
methylene blue
a dark green dye used as a stain, an antiseptic, a chemical indicator, and an antidote in cyanide poisoning
the bivalent radical CH2 derived from methane
an androgenic compound contained in drugs that are used to treat testosterone deficiency and female breast cancer and to stimulate growth and weight gain
Mexican onyx
a hard compact kind of calcite
a light silver-white ductile bivalent metallic element; in pure form it burns with brilliant white flame; occurs naturally only in combination (as in magnesite and dolomite and carnallite and spinel and olivine)
microcosmic salt
a white salt present in urine and used to test for metal oxides
a substance needed only in small amounts for normal body function (e.g., vitamins or minerals)
(trademark) a microscopic and traceable identification particle used to trace explosives or other hazardous materials or to prevent counterfeiting
milk glass
a milky white translucent or opaque glass
milk whey
the serum or watery part of milk that is separated from the curd in making cheese
stout pasteboard used to bind books
a yellow mineral consisting of nickel sulfide; a minor source of nickel
mine pig
pig iron made entirely from ore
solid homogeneous inorganic substances occurring in nature having a definite chemical composition
mineral jelly
a semisolid mixture of hydrocarbons obtained from petroleum; used in medicinal ointments and for lubrication
mineral oil
a distillate of petroleum (especially one used medicinally as a laxative or stool softener)
mineral wool
a light fibrous material used as an insulator
hormone that is one of the steroids of the adrenal cortex that influences the metabolism of sodium and potassium
a reddish oxide of lead (Pb3O4) used as a pigment in paints and in glass and ceramics
the expensive fur of a mink
deep soft mud in water or slush
misch metal
a pyrophoric alloy made from a mixture of rare-earth metals
an agent that triggers mitosis
(chemistry) a substance consisting of two or more substances mixed together (not in fixed proportions and not with chemical bonding)
a hard brittle grey polyvalent metallic element that resembles iron but is not magnetic; used in making steel; occurs in many minerals
a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel
soft suede glove leather from goatskin
any substance used to slow down neutrons in nuclear reactors
loose soil rich in organic matter
(physics and chemistry) the simplest structural unit of an element or compound
Molisch reaction
biochemical indicator of the presence of carbohydrates in a solution; if carbohydrates are present a violet ring is formed by reaction with alpha-naphthol in the presence of sulfuric acid
a mineral resembling graphite that is valued as the chief source of molybdenum and its compounds
molybdenum steel
steel containing 10-15% molybdenum; properties are similar to tungsten steel
(chemistry) an atom having a valence of one
a reddish-brown mineral containing rare earth metals; an important source of thorium and cerium
Monell metal
an alloy of nickel and copper and other metals (such as iron and/or manganese and/or aluminum)
tyrosine with one iodine atom added
a molecule containing one amine group (especially one that is a neurotransmitter)
monoamine neurotransmitter
a monoamine that is functionally important in neural transmission
monobasic acid
an acid containing only one replaceable hydrogen atom per molecule
any of a class of antibodies produced in the laboratory by a single clone of cells or a cell line and consisting of identical antibody molecules
a hydrate that contains one molecule of water per molecule of the compound
a simple compound whose molecules can join together to form polymers
a sugar (like sucrose or fructose) that does not hydrolyse to give other sugars; the simplest group of carbohydrates
monounsaturated fatty acid
an unsaturated fatty acid whose carbon chain has one double or triple valence bond per molecule; found chiefly in olive oil and chicken and almonds
an oxide containing just one atom of oxygen in the molecule
montan wax
a hard wax obtained from lignite
a transparent or translucent gemstone with a pearly luster; some specimens are orthoclase feldspar and others are plagioclase feldspar
a substance used to treat leather or other materials before dyeing; aids in dyeing process
a kind of pink beryl used as a gemstone
a soft pebble-grained leather made from goatskin; used for shoes and book bindings etc.
used as a bond in masonry or for covering a wall
mosaic gold
a yellow pigment sometimes suspended in lacquer
moss agate
an agate resembling moss with brown, black, or green markings
a stringy slimy substance consisting of yeast cells and bacteria; forms during fermentation and is added to cider or wine to produce vinegar
the iridescent internal layer of a mollusk shell
motor oil
oil used to lubricate the moving parts of a motor
a hormone secreted by the anterior pituitary gland that controls the degree of pigmentation in melanocytes
a radioactive transuranic element
mucic acid
a solid acid (C6H10O8) found in milk or sugar
a gelatinous substance secreted by plants
a nitrogenous substance found in mucous secretions; a lubricant that protects body surfaces
any of several glycoproteins similar to mucin
complex polysaccharides containing an amino group; occur chiefly as components of connective tissue
mud pie
a mass of mud that a child has molded into the shape of pie
Muntz metal
a brass that has more zinc and is stronger than alpha brass; used in making castings and hot-worked products
muriatic acid
a former name for hydrochloric acid
a colorless or pale brown mica with potassium
music paper
paper with lines appropriate for writing music
an odorous glandular secretion from the male musk deer; used as a perfume fixative
the brown fur of a muskrat
the smallest unit of DNA where a mutation can occur
mutton tallow
tallow from the body of a mature sheep
a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles (Md is the current symbol for mendelevium but Mv was formerly the symbol)
a toxin produced by a fungus
an antacid
a thin polyester film
a hemoprotein that receives oxygen from hemoglobin and stores it in the tissues until needed
the commonest protein in muscle; a globulin that combines with actin to form actomyosin
myristic acid
a saturated fatty acid occurring naturally in animal and vegetable fats
a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues
a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
a coenzyme present in most living cells and derived from the B vitamin nicotinic acid; serves as a reductant in various metabolic processes
a coenzyme similar to NAD and present in most living cells but serves as a reductant in different metabolic processes
gasoline jelled with aluminum soaps; highly incendiary liquid used in fire bombs and flamethrowers
any of various volatile flammable liquid hydrocarbon mixtures; used chiefly as solvents
a white crystalline strong-smelling hydrocarbon made from coal tar or petroleum and used in organic synthesis and as a fumigant in mothballs
either of two phenols derived from naphthalene
a group of minerals of the zeolite family consisting of a hydrous silicate of sodium and aluminum
natural fiber
fiber derived from plants or animals
natural glass
magma of any composition that cooled very rapidly
natural resin
a plant exudate
a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium
a yellow trivalent metallic element of the rare earth group; occurs in monazite and bastnasite in association with cerium and lanthanum and praseodymium
a colorless odorless gaseous element that give a red glow in a vacuum tube; one of the six inert gasses; occurs in the air in small amounts
neat's-foot oil
a pale yellow oil made from the feet and legs of cattle; used as a dressing for leather
a medicinal liquid preparation intended for use in an atomizer
a sweet liquid secretion that is attractive to pollinators
neem cake
residue after oil is pressed from neem seeds
a synthetic rubber that is resistant to oils and aging; used in waterproof products
a whitish mineral consisting of sodium aluminum silicate or potassium aluminum silicate in crystalline form; used in the manufacture of ceramics and enamels
an igneous rock consisting of nepheline and pyroxene
an amphibole mineral consisting of calcium magnesium silicate in monoclinic crystalline form; a source of jade that is less valuable than from jadeite; once believed to cure kidney disorders
any toxin that affects the kidneys
neroli oil
an odoriferous yellow oil found in orange flowers and used in perfumery and as a flavoring
nerve agent
a toxic gas that is inhaled or absorbed through the skin and has harmful effects on the nervous and respiratory system
any organic substance that occurs in neural activity
any toxin that affects neural tissues
neuromuscular blocking agent
a substance that interferes with the neural transmission between motor neurons and skeletal muscles
a neurochemical that transmits nerve impulses across a synapse
cheap paper made from wood pulp and used for printing newspapers
a protein that is involved in the growth of peripheral nerve cells
a hard malleable ductile silvery metallic element that is resistant to corrosion; used in alloys; occurs in pentlandite and smaltite and garnierite and millerite
Ni-hard iron
cast iron to which nickel has been added to make it resist abrasion
Ni-resist iron
cast iron consisting of graphite in a matrix of austenite
a B vitamin essential for the normal function of the nervous system and the gastrointestinal tract
an alloy of nickel and chromium with high electrical resistance and an ability to withstand high temperatures; used for resistance heating elements
nickel alloy
an alloy whose main constituent is nickel
nickel bronze
a bronze containing up to 30% nickel
nickel steel
an alloy steel containing nickel
an alkaloid poison that occurs in tobacco; used in medicine and as an insecticide
night soil
human excreta used as fertilizer
(KNO3) used especially as a fertilizer and explosive
a yellow crystalline explosive solid that is used in detonators
any compound containing the nitrate group (such as a salt or ester of nitric acid)
nitric oxide
a poisonous red-brown gas (NO)
a compound containing nitrogen and a more electropositive element (such as phosphorus or a metal)
the radical -NO2 or any compound containing it (such as a salt or ester of nitrous acid)
nitro group
the group -NO3
a poisonous oily water-soluble liquid used as a solvent and in the manufacture of aniline
the mineral form of calcium nitrate
gaseous form of chloropicrin used as tear gas
derivative of furan used to inhibit bacterial growth
nitrogen dioxide
a highly poisonous brown gas (NO2)
nitrogen mustard
a toxic compound resembling mustard gas in structure; important in cancer treatment
nitrogen oxide
any of several oxides of nitrogen formed by the action of nitric acid on oxidizable materials; present in car exhausts
an enzyme of nitrogen-fixing microorganisms that catalyzes the conversion of nitrogen to ammonia
a heavy yellow poisonous oily explosive liquid obtained by nitrating glycerol; used in making explosives and medically as a vasodilator (trade names Nitrospan and Nitrostat)
nitrous acid
an unstable inorganic acid known only in solution and as nitrite salts
a radioactive transuranic element synthesized by bombarding curium with carbon ions; 7 isotopes are known
noble metal
any metal that is resistant to corrosion or oxidation
noncoding DNA
sequence of a eukaryotic gene's DNA that is not translated into a protein
a chemical element lacking typical metallic properties
an organic compound that does no contain a steroid
a progesterone derivative used in oral contraceptives and in the control of menstruation and the treatment of abnormal uterine bleeding
synthetic progestin used in oral contraceptives
a synthetic progestational hormone (trade name Norlutin) used in oral contraceptives and to treat endometriosis
a pad of paper for keeping notes
a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium
nuclear fuel
fuel (such as uranium) that can be used in nuclear reactors as a source of electricity
nuclear RNA
ribonucleic acid found in the nucleolus of the cell
general term for enzymes that catalyze the hydrolysis of nucleic acid by cleaving chains of nucleotides into smaller units
nucleic acid
(biochemistry) any of various macromolecules composed of nucleotide chains that are vital constituents of all living cells
any of several substances found in the nuclei of all living cells; consists of a protein bound to a nucleic acid
a glycoside formed by partial hydrolysis of a nucleic acid
nurse log
a large decomposing tree trunk that has fallen, usually in a forest; the decaying wood provides moisture and nutrients for a variety of insects and plants
a thermoplastic polyamide; a family of strong resilient synthetic fibers
a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
loose hemp or jute fiber obtained by unravelling old ropes; when impregnated with tar it was used to caulk seams and pack joints in wooden ships
obidoxime chloride
a chloride used as an antidote for nerve gases such as sarin or VX
acid or granitic glass formed by the rapid cooling of lava without crystallization; usually dark, but transparent in thin pieces
any of various earths containing silica and alumina and ferric oxide; used as a pigment
octadecanoic acid
a waxy saturated fatty acid; occurs widely as a glyceride in animal and vegetable fats
any isomeric saturated hydrocarbon found in petroleum and used as a fuel and solvent
octanedioic acid
a dicarboxylic acid found in cork
a slippery or viscous liquid or liquefiable substance not miscible with water
oil of turpentine
volatile liquid distilled from turpentine oleoresin; used as paint thinner and solvent and medicinally
oil of vitriol
(H2SO4) a highly corrosive acid made from sulfur dioxide; widely used in the chemical industry
oil shale
shale from which oil can be obtained by heating
oil-hardened steel
steel that is quenched in oil
paper that has been made translucent and waterproof by soaking in oil
leaf or strip from a leaf of the talipot palm used in India for writing paper
oleic acid
a colorless oily liquid occurring as a glyceride; it is the major fatty acid in olive oil and canola oil; used in making soap and cosmetics and ointments and lubricating oils
a naturally occurring glyceride of oleic acid that is found in fats and oils
oleo oil
obtained from beef fat; used in making margarine and soap and in lubrication
a naturally occurring mixture of a resin and an essential oil; obtained from certain plants
oleoresin capiscum
an oleoresin extracted from the capsicum pepper plant
(biochemistry) a polynucleotide whose molecules contain relatively few nucleotides
any of a series of triclinic feldspars that form rocks
any of the carbohydrates that yield only a few monosaccharide molecules on complete hydrolysis
rare green to black mineral consisting of hydrated copper arsenate that is found in copper deposits
a mineral consisting of magnesium iron silicate; a source of magnesium
a polyunsaturated fatty acid whose carbon chain has its first double valence bond three carbons from the beginning
a polyunsaturated fatty acid whose carbon chain has its first double valence bond six carbons from the beginning
a chalcedony with alternating black and white bands; used in making cameos
ooze leather
a very soft leather made from the skins of calves and having a suede finish on the flesh side
a translucent mineral consisting of hydrated silica of variable color; some varieties are used as gemstones
opaque gem
a gemstone that is opaque
an odorous gum resin formerly used in medicines
retinal protein formed by the action of light on rhodopsin
an antibody in blood serum that attaches to invading microorganisms and other antigens to make them more susceptible to the action of phagocytes
optical glass
clear homogeneous glass of known refractive index; used to make lenses
any pigment producing the orange color
a mineral that contains metal that is valuable enough to be mined
alloy of copper and tin and zinc; used in imitation gold jewelry
organic compound
any compound of carbon and another element or a radical
a fertilizer that is derived from animal or vegetable matter
an insecticide that interferes with an insect's nervous system
organophosphate nerve agent
any of a series of nerve agents containing organophosphate compounds first synthesized by German chemists in 1936; in World War II the Germans tested them in concentration camps but not on the battlefield; Iraq is alleged to have used them against Iran and against the Kurds
brass that looks like gold; used to decorate furniture
an amino acid that does not occur in proteins but is important in the formation of urea
a yellow mineral occurring in conjunction with realgar; an ore of arsenic
a white or colored monoclinic feldspar
orthophosphoric acid
an acid used in fertilizers and soaps: H3PO4
a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
Otaheite arrowroot starch
a starch obtained from the root of the pia
the fur of an otter
a salt or ester of oxalacetic acid
oxalacetic acid
an acid formed by oxidation of maleic acid (as in metabolism of fats and carbohydrates)
a salt or ester of oxalic acid
a substance that oxidizes another substance
any of the enzymes that catalyze biological oxidation
oxidation-reduction indicator
an indicator that shows a reversible color change between oxidized and reduced forms
any compound of oxygen with another element or a radical
oxidized LDL cholesterol
LDL cholesterol that has been bombarded by free radicals; it is thought to cause atherosclerosis
an enzyme that catalyzes oxidation-reduction
any compound containing the group -C=NOH
a mixture of oxygen and acetylene; used to create high temperatures for cutting or welding metals
any acid that contains oxygen
an oxidoreductase that catalyzes the incorporation of molecular oxygen
the bright red hemoglobin that is a combination of hemoglobin and oxygen from the lungs
a colorless gas (O3) soluble in alkalis and cold water; a strong oxidizing agent; can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)
any of a class of unstable chemical compounds resulting from the addition of ozone to a double bond in an unsaturated compound
a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms
a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
a metabolic acid found in yeast and liver cells; used to make dyes and drugs and sun blockers
any material used especially to protect something
a number of sheets of paper fastened together along one edge
freely flowing lava
an ester of glycerol and palmitic acid
extract from the pancreas of animals that contains pancreatic enzymes; used to treat pancreatitis and other conditions involving insufficient pancreatic secretions
a roofing tile with a S-shape; laid so that curves overlap
a vitamin of the vitamin B complex that performs an important role in the oxidation of fats and carbohydrates and certain amino acids; occurs in many foods
a proteolytic enzyme obtained from the unripe papaya; used as a meat tenderizer
a material made of cellulose pulp derived mainly from wood or rags or certain grasses
paper tape
a long narrow strip of paper
paper toweling
absorbent paper used as toweling
a substance made from paper pulp that can be molded when wet and painted when dry
a cardboard suitable for making posters
paper made from the papyrus plant by cutting it in strips and pressing it flat; used by ancient Egyptians and Greeks and Romans
Para rubber
a type of natural rubber obtained from tropical South American trees
paraffin scale
partly refined paraffin wax
(British usage) kerosine
from crude petroleum; used for candles and for preservative or waterproof coatings
a colorless or pale brown mica with sodium
a poisonous yellow solid used in solution as a herbicide
a colorless and odorless toxic oil used as an insecticide
a superior paper resembling sheepskin
plaster used to coat outer walls and line chimneys
Paris green
a toxic double salt of copper arsenate and copper acetate
a small discrete mass of solid or liquid matter that remains individually dispersed in gas or liquid emissions (usually considered to be an atmospheric pollutant)
a hard, brilliant lead glass that is used in making artificial jewelry
any mixture of a soft and malleable consistency
stiff cardboard made by pasting together layers of paper
patent leather
leather with a hard glossy surface
material used to pave an area
pay dirt
ore that yields a substantial profit to the miner
Payne's grey
any pigment that produces a greyish to dark greyish blue
a soft heavy toxic malleable metallic element; bluish white when freshly cut but tarnishes readily to dull grey
a solution containing a phosphate buffer
a silver-white metallic element of the platinum group that resembles platinum; occurs in some copper and nickel ores; does not tarnish at ordinary temperatures and is used (alloyed with gold) in jewelry
pearl ash
an impure form of potassium carbonate
pearl sago
sago ground into small round grains
a lamellar mixture of cementite and ferrite formed during the cooling of austenite; a constituent of steel and cast iron
partially carbonized vegetable matter saturated with water; can be used as a fuel when dried
pectic acid
a complex acid that occurs in ripe fruit and some vegetables
any of various water-soluble colloidal carbohydrates that occur in ripe fruit and vegetables; used in making fruit jellies and jams
a glucocorticoid (trade names Pediapred or Prelone) used to treat inflammatory conditions
a chemical agent that kills lice
liquid excretory product
a form of igneous rock consisting of extremely coarse granite resulting from the crystallization of magma rich in rare elements
graphite (or a similar substance) used in such a way as to be a medium of communication
pentanoic acid
a clear liquid carboxylic acid used in perfumes and drugs
a mineral (iron and nickel sulphide) that is the chief ore of nickel
any monosaccharide sugar containing five atoms of carbon per molecule
an oxide containing five atoms of oxygen in the molecule
an enzyme produced in the stomach that splits proteins into peptones
precursor of pepsin; stored in the stomach walls and converted to pepsin by hydrochloric acid in the stomach
any enzyme that catalyzes the splitting of proteins into smaller peptide fractions and amino acids by a process known as proteolysis
amide combining the amino group of one amino acid with the carboxyl group of another; usually obtained by partial hydrolysis of protein
an antacid
any of various water-soluble compounds that form by hydrolysis in the digestion of proteins to amino acids
perboric acid
a form of boric acid
a salt of perchloric acid
perchloric acid
a powerful oxidizing agent; forms perchlorates
a chloride containing an unusually high proportion of chlorine
the product of percolation
a pale green variety of chrysolite; used as a gemstone
a dark coarse-grained igneous rock consisting principally of olivine
periodic acid
any acid of iodine that contains oxygen
an 80/20 alloy of nickel and iron; easily magnetized and demagnetized
a dark purple salt of permanganic acid; in water solution it is used as a disinfectant and antiseptic
permanganate of potash
a poisonous salt that forms dark purple crystals and is purple-red when dissolved in water; used as an oxidizing and bleaching agent and as a disinfectant and antiseptic
permanganic acid
an unstable purple acid (HMnO4) known only in solution or of permanganate salts
any of a group of enzymes (occurring especially in plant cells) that catalyze the oxidation of a compound by a peroxide
an inorganic compound containing the divalent ion -O-O-
Persian lamb
the fur of a karakul lamb
a transparent thermoplastic acrylic resin
a chemical used to kill pests (as rodents or insects)
any compound obtained from petroleum or natural gas
any of various alloys of tin with small amounts of other metals (especially lead)
a powerful greenhouse gas emitted during the production of aluminum
a purplish red water-soluble dye used in microscopy
any of a class of weakly acidic organic compounds; molecule contains one or more hydroxyl groups
phenolic plastic
a plastic consisting of phenolic resins
a thermosetting resin
a compound used primarily in veterinary medicine to rid farm animals of internal parasites
phenyl salicylate
a white powder with a pleasant taste and odor; used to absorb light in sun tan lotions or as a preservative or an antiseptic or a coating for pills in which the medicine is intended for enteric release
an essential amino acid found in proteins and needed for growth of children and for protein metabolism in children and adults; abundant in milk and eggs; it is normally converted to tyrosine in the human body
a chemical substance secreted externally by some animals (especially insects) that influences the physiology or behavior of other animals of the same species
a group of white or reddish crystalline minerals of the zeolite family consisting of a hydrous silicate of calcium and potassium and aluminum
a hypothetical substance once believed to be present in all combustible materials and to be released during burning
a brown form of mica consisting of hydrous silicate of potassium and magnesium and aluminum
a colorless poisonous gas that smells like new-mown hay; used in chemical warfare
any of a group of enzymes that act as a catalyst in the hydrolysis of organic phosphates
a colorless gas with a strong fishy smell; used as a pesticide
any of various compounds composed of fatty acids and phosphoric acid and a nitrogenous base; an important constituent of membranes
containing chemically bound phosphoric acid
a synthetic substance that is fluorescent or phosphorescent; used to coat the screens of cathode ray tubes
phosphor bronze
a corrosion-resistant bronze containing phosphorus; used in bearings and gears
a special pigment found in the rods and cones of the retina
phthalic acid
a colorless acid used to make dyes and perfumes
phthalic anhydride
a white cyclic anhydride
a chemical substance obtained from plants that is biologically active but not nutritive
any substance produced by plants that is similar in its properties to extracellular bacterial toxin
picric acid
a yellow toxic highly explosive strong acid; used in high explosives and as a dye and in chemical reactions
pig iron
crude iron tapped from a blast furnace
pig lead
lead that is cast in pigs
pigeon droppings
droppings of pigeons
dry coloring material (especially a powder to be mixed with a liquid to produce paint, etc.)
any substance whose presence in plant or animal tissues produces a characteristic color
leather from the skin of swine
pillow lava
lava that hardened in rounded shapes suggestive of pillows; believed to result from underwater eruptions
pina cloth
a fine cloth made from pineapple fibers
an alloy of copper and zinc that is used in cheap jewelry to imitate gold
pine knot
a joint of pine wood used for fuel
pine tar
a dark viscous substance obtained from the destructive distillation of pine wood
grey or green or brown mineral similar to mica and containing aluminum and potassium sulphates
fine white clay used in making tobacco pipes and pottery and in whitening leather
derived from pepper (especially black pepper); source of the hotness of black and white pepper
pisang wax
a wax obtained from the leaves of a plantain
any of various dark heavy viscid substances obtained as a residue
a mineral consisting of uranium oxide and trace amounts of radium and thorium and polonium and lead and helium; uraninite in massive form is called pitchblende which is the chief uranium ore
dark acid granitic glass
planks collectively; a quantity of planks
plant fiber
fiber derived from plants
plant material
material derived from plants
plant product
a product made from plant material
a green slightly translucent variety of chalcedony used as a gemstone
plasma protein
any of the proteins in blood plasma
an inactive form of plasmin that occurs in plasma and is converted to plasmin by organic solvents
plasminogen activator
protease produced in the kidney that converts plasminogen to plasmin and so initiates fibrinolysis
a mixture of lime or gypsum with sand and water; hardens into a smooth solid; used to cover walls and ceilings
plaster of Paris
any of several gypsum cements; a white powder (a form of calcium sulphate) that forms a paste when mixed with water and hardens into a solid; used in making molds and sculptures and casts for broken limbs
generic name for certain synthetic or semisynthetic materials that can be molded or extruded into objects or films or filaments or used for making e.g. coatings and adhesives
a synthetic material resembling clay but remaining soft; used as a substitute for clay or wax in modeling (especially in schools)
a substance added to plastics or other materials to make them more pliable
platinum black
a fine black powder of platinum; used as a catalyst in chemical reactions
a light transparent weather resistant thermoplastic
plutonium 239
a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel; produced by irradiating uranium 238 with slow electrons
a soft silvery metallic element of the rare earth group having no stable isotope; was discovered in radioactive form as a fission product of uranium
a radioactive metallic element that is similar to tellurium and bismuth; occurs in uranium ores but can be produced by bombarding bismuth with neutrons in a nuclear reactor
a soil that develops in temperate to cold moist climates under coniferous or heath vegetation; an organic mat over a grey leached layer
poison gas
a gas that is poisonous to breath or contact; used in chemical warfare
any substance that causes injury or illness or death of a living organism
a preparation used in polishing
a rare mineral that is an important source of cesium
waste matter that contaminates the water or air or soil
a polymer containing repeated amide groups
a polymer of butylene; used in lubricants and synthetic rubber
an electrolyte of high molecular weight
a complex ester used for making fibers or resins or plastics or as a plasticizer
any of numerous synthetic resins; they are light and strong and weather resistant
polyester fiber
a quick-drying resilient synthetic fiber consisting primarily of polyester
a lightweight thermoplastic; used especially in packaging and insulation
a foam made by adding water to polyurethane plastics
a naturally occurring or synthetic compound consisting of large molecules made up of a linked series of repeated simple monomers
an enzyme that catalyzes the formation of new DNA and RNA from an existing strand of DNA or RNA
polymethyl methacrylate
a transparent plastic used as a substitute for glass
(biochemistry) a linear polymer whose molecule is composed of many nucleotide units constituting a section of a nucleic acid molecule
any of a class of carbohydrates whose molecules contain chains of monosaccharide molecules
a peptide containing 10 to more than 100 amino acids
a salt or ester of polyphosphoric acid
polyphosphoric acid
a series of oxyacids of phosphorus
a polymer of propylene used as a thermoplastic molding material
a polymer of styrene; a rigid transparent thermoplastic
polyunsaturated fat
a class of fats having long carbon chains with many double bonds unsaturated with hydrogen atoms; used in some margarines; supposedly associated with low blood cholesterol
polyunsaturated fatty acid
an unsaturated fatty acid whose carbon chain has more than one double or triple valence bond per molecule; found chiefly in fish and corn and soybean oil and safflower oil
any of various polymers containing the urethane radical; a wide variety of synthetic forms are made and used as adhesives or plastics or paints or rubber
polyvinyl resin
a thermoplastic derived by polymerization from compounds containing the vinyl group
a polymer of vinyl formaldehyde
any of various pigments distributed widely in living tissues
porphyritic rock
any igneous rock with crystals embedded in a finer groundmass of minerals
porpoise oil
a yellow fatty oil obtained from porpoises and used as a fine lubricant
Portland cement
a cement that hardens under water; made by heating limestone and clay in a kiln and pulverizing the result
pot metal
cast iron used for making cooking wares
pot metal
an alloy of copper and lead used especially for making large pots
potassium acid carbonate
a crystalline salt (KHCO3) that is used in baking powder and as an antacid
potassium bromide
a white crystalline salt (KBr) used as a sedative and in photography
potassium carbonate
a white salt (K2CO3) that is basic in solution; used to make glass and cleansing agents
potassium chlorate
a white salt (KClO3) used in matches, fireworks, and explosives; also used as a disinfectant and bleaching agent
potassium cyanide
a poisonous salt (KCN) used in electroplating and in photography
potassium dichromate
an orange-red salt used in making dyes and in photography
potassium ferrocyanide
a cyanide compound that is prepared by the reaction of potassium cyanide with ferrous salts; commonly used by gardeners
potassium iodide
a crystalline salt in organic synthesis and in making photographic emulsions and in iodized table salt
potter's clay
clay that does not contain any iron; used in making pottery or for modeling
a solid substance in the form of tiny loose particles; a solid that has been pulverized
a soft yellowish-white trivalent metallic element of the rare earth group; can be recovered from bastnasite or monazite by an ion-exchange process
prairie soil
a type of soil occurring under grasses in temperate climates
an agent that causes a precipitate to form
a precipitated solid substance in suspension or after settling or filtering
an antibody that causes precipitation when it unites with its antigen
a substance from which another substance is formed (especially by a metabolic reaction)
a compound found in women's urine during certain phases of the menstrual cycle and in the urine of pregnant women
a chemical compound that is added to protect against decay or decomposition
antacid (trade name Prevacid) that suppresses acid secretion in the stomach
antacid (trade name Prilosec) that suppresses acid secretion in the stomach
primary solid solution
a homogeneous solid that can exist over a range of component chemicals; a constituent of alloys that is formed when atoms of an element are incorporated into the crystals of a metal
printer's ink
a semisolid quick drying ink made especially for use in printing
a chemical substance formed as a result of a chemical reaction
any of a group of compounds that are inactive precursors of enzymes and require some change (such as the hydrolysis of a fragment that masks an active enzyme) to become active
any of a group of steroid hormones that have the effect of progesterone
a simple protein found in plants
an amino acid that is found in many proteins (especially collagen)
a colorless liquid aldehyde
the amide of propionic acid (C2H5CONH2)
colorless gas found in natural gas and petroleum; used as a fuel
a sweet colorless, viscous, hygroscopic liquid used as an antifreeze and in brake fluid and also as a humectant in cosmetics and personal care items although it can be absorbed through the skin with harmful effects
propanoic acid
a liquid fatty acid found in milk and sweat and in fuel distillates
a clear colorless volatile liquid (alcohol) used as a solvent and antiseptic
any substance that propels
a flammable gas obtained by cracking petroleum; used in organic synthesis
the monovalent organic group C3H7- obtained from propane
a crystalline compound used as an antithyroid drug in the treatment of goiter
a simple protein found in fish sperm; rich in arginine; simpler in composition than globulin or albumin; counteracts the anticoagulant effect of heparin
any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes
the full complement of proteins produced by a particular genome
a progestin compound (trade name Provera) used to treat menstrual disorders
cDNA copy of the RNA genome of a retrovirus; the genetic material of a virus as incorporated into and able to replicate with the genome of a host cell
vitamin precursor; a substance that is converted into a vitamin in animal tissues
provitamin A
an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver
Prussian blue
any of various blue pigments
a protein manufactured exclusively by the prostate gland; PSA is produced for the ejaculate where it liquifies the semen and allows sperm cells to swim freely; elevated levels of PSA in blood serum are associated with benign prostatic hyperplasia and prostate cancer
poisonous crystalline alkaloid occurring with ephedrine and isomorphic with it
a mineral consisting of hydrated basic oxide of manganese and barium; a source of manganese
a heavy precious metallic element; grey-white and resistant to corroding; occurs in some nickel and copper ores and is also found native in some deposits
any of various amines (such as putrescine or cadaverine) formed by the action of putrefactive bacteria
an amylase secreted in saliva
a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239
a mixture of wet clay and sand that can be used to line a pond and that is impervious to water when dry
a mixture of cellulose fibers
softwood used to make paper
a light glass formed on the surface of some lavas; used as an abrasive
substance that smolders when ignited; used to light fuses (especially fireworks)
a colorless crystalline organic base containing nitrogen; the parent compound of various biologically important substances
any of several bases that are derivatives of purine
a colorless crystalline ptomaine with a foul odor that is produced in decaying animal matter
a dough-like mixture of whiting and boiled linseed oil; used especially to patch woodwork or secure panes of glass
a vinyl polymer used especially in paints or adhesives
a polymer of vinyl chloride used instead of rubber in electric cables
any substance that can cause a rise in body temperature
a pale yellow crystalline hydrocarbon C16H10 extracted from coal tar
a borosilicate glass with a low coefficient of expansion; used for heat-resistant glassware in cooking and chemistry
a toxic colorless flammable liquid organic base with a disagreeable odor; usually derived from coal
a heterocyclic organic compound with a penetrating odor
any of several basic compounds derived from pyrimidine
any of various metallic-looking sulfides (of which pyrite is the commonest)
nitrocellulose containing less nitrogen than guncotton; used in making smokeless powder
pyrogallic acid
a toxic white lustrous crystalline phenol used to treat certain skin diseases and as a photographic developer
any substance characterized by its great flammability
pyroligneous acid
a red-brown liquid formed in distillation of wood which contains acetic acid, methanol, acetone, wood oils, and tars
a mineral consisting of manganese dioxide; an important source of manganese
a deep red garnet used as a gemstone
pyrophoric alloy
an alloy that emits sparks when struck or scratched with steel; used in lighter flints
a salt or ester of pyrophosphoric acid
pyrophosphoric acid
a solid acid formed by reactions of orthophosphoric acid
a white or greenish aluminum silicate mineral (resembles talc)
any of a group of crystalline silicate mineral common in igneous and metamorphic rocks
highly flammable nitrocellulose used in making collodion and plastics and lacquers
pyruvic acid
a colorless acid formed as an important intermediate in metabolism or fermentation
a hard glossy mineral consisting of silicon dioxide in crystal form; present in most rocks (especially sandstone and granite); yellow sand is quartz with iron oxide impurities
hard metamorphic rock consisting essentially of interlocking quartz crystals
a bitter compound used as an insecticide and tonic and vermifuge; extracted from the wood and bark of trees of the genera Quassia and Picrasma
quaternary ammonium compound
a compound derived from ammonium with hydrogen atoms replaced by organic groups; used as surface-active agents, disinfectants, and in drugs
quenched steel
steel that has been hardened by immersing it in water or oil to cool it
a yellow dye made from the bark of the quercitron oak tree
an intensely radioactive metallic element that occurs in minute amounts in uranium ores
the fur of the North American racoon
racemic acid
the optically inactive form of tartaric acid that is often found in grape juice
a red iron ore used in dyeing and marking
radioactive material
material that is radioactive
radioactive waste
useless radioactive materials that are left after some laboratory or commercial process is completed
a radioactive isotope of chlorine
a radioactive isotope of an element; produced either naturally or artificially
radiopaque dye
dye that does not allow the passage of X rays or other radiation; used to outline certain organs during X-ray examination
radioactive isotope of thorium with mass number 228
leaf fibers of the raffia palm tree; used to make baskets and mats etc.
a trisaccharide that occurs in sugar beets and cotton seeds and certain cereals
rag paper
paper made partly or wholly from rags
ragweed pollen
pollen of the ragweed plant is a common allergen
drops of fresh water that fall as precipitation from clouds
any of several alkaloids extracted from the shrub Rauwolfia serpentina
a bit of fiber that has become separated from woven fabric
raw material
material suitable for manufacture or use or finishing
raw sienna
a yellowish-brown pigment made from untreated sienna
raw umber
greenish brown pigment
raw wood
wood that is not finished or painted
raw wool
wool in its natural condition; not refined or processed
untanned hide especially of cattle; cut in strips it is used for whips and ropes
a soft silvery metallic element of the alkali metal group; burns in air and reacts violently in water; occurs in carnallite and lepidolite and pollucite
a rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum
a chemical substance that is present at the start of a chemical reaction
a chemical agent for use in chemical reactions
an immunoglobulin E that is formed as an antibody against allergens (such as pollen); attaches to cell membranes causing the release of histamine and other substances responsible for the local inflammation characteristic of an allergy
a rare soft orange mineral consisting of arsenic sulphide; an important ore of arsenic
recombinant DNA
genetically engineered DNA made by recombining fragments of DNA from different organisms
recombinant protein
a protein derived from recombinant DNA
used or abandoned materials for use in creating new products
red clay
clay whose redness results from iron oxide
red fire
combustible material (usually salts of lithium or strontium) that burns bright red; used in flares and fireworks
red silk cotton
a plant fiber from the red silk-cotton tree of eastern India; inferior to kapok
red tide
seawater that is discolored by large numbers of certain dinoflagellates that produce saxitoxin
red-lead putty
a cement resembling putty; made by mixing white and red lead in boiled linseed oil; used as luting on pipe fittings
a substance capable of bringing about the reduction of another substance as it itself is oxidized; used in photography to lessen the density of a negative or print by oxidizing some of the loose silver
an enzyme that catalyses the biochemical reduction of some specified substance
any substance used to provide cooling (as in a refrigerator)
a type of soil consisting of unconsolidated material from freshly deposited alluvium or sand
a rich black loam of India
a monoclonal antibody (trade name Remicade) used to treat Crohn's disease and rheumatoid arthritis; administered by infusion; use and dosage must be determined by a physician
a solvent that removes a substance (usually from a surface)
a substance similar to stucco but exclusively applied to masonry walls
a proteolytic enzyme secreted by the kidneys; catalyzes the formation of angiotensin and thus affects blood pressure
a substance that curdles milk in making cheese and junket
a kind of soft talc; sometimes used as wood filler
a chemical substance that repels animals
a compound with which fabrics are treated to repel water
oil products that remain after petroleum has been distilled
residual clay
the soil that is remaining after the soluble elements have been dissolved
matter that remains after something has been removed
any of a class of solid or semisolid viscous substances obtained either as exudations from certain plants or prepared by polymerization of simple molecules
a plastic containing resins
a crystalline phenol obtained from various resins; used in ointments for acne and in dandruff shampoos
a chemical that is added to a photographic developer in order to retard development and reduce the amount of fog on a film
restriction endonuclease
any of the enzymes that cut nucleic acid at specific restriction sites and produce restriction fragments; obtained from bacteria (where they cripple viral invaders); used in recombinant DNA technology
a renewed suspension of insoluble particles after they have been precipitated
retinal purple
a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light
either of two yellow to red retinal pigments formed from rhodopsin by the action of light
reverse transcriptase
a polymerase that catalyzes the formation of DNA using RNA as a template; found especially in retroviruses
a substance produced by the hypothalamus that is capable of accelerating the secretion of a given hormone by the anterior pituitary gland
a radioactive transuranic element
a white hard metallic element that is one of the platinum group and is found in platinum ores; used in alloys with platinum
Rh antibody
rhesus factor antibody
Rh factor
a blood group antigen possessed by Rh-positive people; if an Rh-negative person receives a blood transfusion from an Rh-positive person it can result in hemolysis and anemia
a watery discharge from the mucous membranes (especially from the eyes or nose)
an imitation diamond made from rock crystal or glass or paste
a mineral consisting of manganese carbonate; a source of manganese
a red or pink variety of garnet used as a gemstone
a pink or red mineral consisting of crystalline manganese silicate; used as an ornamental stone
very acid volcanic rock
a pentose sugar important as a component of ribonucleic acid
rice paper
a thin delicate material resembling paper; made from the rice-paper tree
a toxic protein extracted from castor beans; used as a chemical reagent; can be used as a bioweapon
ricinoleic acid
an oily fatty acid found in castor oil and used in soap
ridge tile
a decorative tile that is bent in cross section; used to cover the ridge of a roof
Ringer's solution
an aqueous solution containing the chlorides of sodium and potassium and calcium that is isotonic to animal tissues; used to correct dehydration and (in physiological experiments) as a medium for in vitro preparations
a liquid preparation used on wet hair to give it a tint
a radioactive gaseous element formed by the disintegration of radium; the heaviest of the inert gasses; occurs naturally (especially in areas over granite) and is considered a hazard to health
(biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes; it transmits genetic information from DNA to the cytoplasm and controls certain chemical processes in the cell
RNA polymerase
the enzyme that copies DNA into RNA
a transferase that catalyzes the hydrolysis of ribonucleic acid
road metal
broken rock used for repairing or making roads
a soft sheepskin leather that is colored and finished to resemble morocco; used in bookbinding
Rochelle salts
a double salt used in Seidlitz powder; acts as a cathartic
rock crystal
a clear quartz used in making electronic and optical equipment
material consisting of the aggregate of minerals like those making up the Earth's crust
rocket fuel
an explosive charge that propels a rocket
an antacid
roofing material
building material used in constructing roofs
roofing paper
a heavy paper impregnated with tar and used as part of a roof for waterproofing
roofing tile
a thin flat slab of fired clay used for roofing
rose quartz
a translucent rose-red variety of quartz used for ornaments
a white crystalline insecticide that has low toxicity for mammals; is used in home gardens; extracted from the roots of derris and cube
a weathered and decomposed siliceous limestone; in powdered form it is used in polishing
a coarse plaster for the surface of external walls
royal jelly
a secretion of the pharyngeal glands of bees that is fed to very young larvae and to bees destined to be queens
a rare polyvalent metallic element of the platinum group; it is found associated with platinum
rubber cement
an adhesive made by dissolving unvulcanized rubber in a solvent like benzene or naphtha
any of various synthetic elastic materials whose properties resemble natural rubber
worthless material that is to be disposed of
a yellow or orange variety of ruby spinel
a transparent deep red variety of corundum; used as a gemstone and in lasers
ruby spinel
a spinel used as a gemstone (usually dark red)
rudaceous rock
a sedimentary rock formed of coarse-grained material
Russia leather
a smooth leather tanned with willow, birch, or oak, and scented on the flesh side with birch oil
a red or brown oxide coating on iron or steel caused by the action of oxygen and moisture
rust inhibitor
antioxidant that inhibits the formation of rust
a mineral consisting of titanium dioxide in crystalline form; occurs in metamorphic and plutonic rocks and is a major source of titanium
an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)
the expensive dark brown fur of the marten
saccharic acid
a white dicarboxylic acid formed from oxidation of sugar or starch
a complex carbohydrate found in many plants and used as a sweetening agent
any of a class of chiefly red organic dyes
powdery starch from certain sago palms; used in Asia as a food thickener and textile stiffener
sal soda
a sodium salt of carbonic acid; used in making soap powders and glass and paper
sal volatile
a solution of ammonium carbonate in ammonia water and alcohol
a salt of salicylic acid (included in several commonly used drugs)
an isotonic solution of sodium chloride and distilled water
salmon oil
a fatty oil obtained from the wastes in canning salmon; used in making soap and dressing leather
a compound formed by replacing hydrogen in an acid by a metal (or a radical that acts like a metal)
a complex black mineral occurring in pegmatites
a loose material consisting of grains of rock or coral
a sedimentary rock consisting of sand consolidated with some cement (clay or quartz etc.)
a watery solution of sugars, salts, and minerals that circulates through the vascular system of a plant
any of various plant glucosides that form soapy lathers when mixed and agitated with water; used in detergents and foaming agents and emulsifiers
a precious transparent stone of rich blue corundum valued as a gemstone
a rare light blue or green mineral; consists of aluminum and magnesium silicate and occurs as small grains in some metamorphic rocks
a deposit of clay and disintegrating rock that is found in its original place
sludge (rich in organic matter) that accumulates at the bottom of lakes or oceans
any of various thermoplastic resins used to make things
a sweetish crystalline amino acid
a deep orange-red variety of chalcedony
sardine oil
oil obtained from sardines and used chiefly as a lubricant and in soap
an onyx characterized by parallel layers of sard and a different colored mineral
saturated fatty acid
a fatty acid whose carbon chain cannot absorb any more hydrogen atoms; found chiefly in animal fats
saw log
log large enough to be sawed into boards
fine particles of wood made by sawing wood
a powerful neurotoxin produced by certain dinoflagellates found in red tides; it can accumulate in mollusks that feed on the dinoflagellates and cause food poisoning to humans
a metallic element having four allotropic forms; used in a wide variety of alloys; found in stibnite
a white trivalent metallic element; sometimes classified in the rare earth group; occurs in the Scandinavian mineral thortveitite
a drug that destroys the itch mite that causes scabies
a chemical agent that is added to a chemical mixture to counteract the effects of impurities
a mineral used as an ore of tungsten
any metamorphic rock that can be split into thin layers
black tourmaline
scrap iron
iron to be melted again and reworked
scrap metal
discarded metal suitable for reprocessing
scratch pad
pad for preliminary or hasty writing or notes or sketches etc
a toxic nonmetallic element related to sulfur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulfide ores (as pyrite)
sea coal
pulverized bituminous coal; used as a foundry facing
sea spray
spray from ocean waves
seal oil
a pale yellow to red-brown fatty oil obtained from seal blubber; used in making soap and dressing leather and as a lubricant
the pelt or fur (especially the underfur) of a seal
a kind of sealing material that is used to form a hard coating on a porous surface (as a coat of paint or varnish used to size a surface)
sealing material
any substance used to seal joints or fill cracks in a porous surface
a set of enzymes believed to snip pieces off a longer protein producing fragments of amyloid protein that bunch up and create amyloid protein plaques in brain tissue (the pathological hallmark of Alzheimer's)
sedimentary clay
clay soil formed by sedimentary deposits
sedimentary rock
rock formed from consolidated clay sediments
seed lac
granular material obtained from stick lac by crushing and washing
Seidlitz powders
an effervescing salt containing sodium bicarbonate and Rochelle salt and tartaric acid; used as a cathartic
selenic acid
a strong acid (H2SeO4) analogous to sulfuric acid
semiconducting material
a substance as germanium or silicon whose electrical conductivity is intermediate between that of a metal and an insulator; its conductivity increases with temperature and in the presence of impurities
Senegal gum
gum arabic from the vicinity of the Senegal river
(chemistry) a substance other than a catalyst that facilitates the start of a catalytic reaction
rich brown pigment prepared from the ink of cuttlefishes
a sweetish crystalline amino acid involved in the synthesis by the body of cysteine
serum albumin
albumin occurring in blood serum; serves to maintain the somatic pressure of the blood
serum globulin
globulins occurring in blood serum and containing most of the antibodies of the blood
waste matter carried away in sewers or drains
sewer gas
foul-smelling gas that forms in sewers
sex hormone
any hormone affecting the development and growth of sex organs
a transuranic element
a strong coarse tobacco that has been shredded
building material used as siding or roofing
a sedimentary rock formed by the deposition of successive layers of clay
shale oil
oil extracted from oil shale by heating
shark oil
a fatty yellow to brown oil obtained from the livers of sharks; used for dressing leather and as a source of vitamin A
sheep dip
a liquid mixture containing pesticides in which sheep are dipped to kill parasites
the material that forms the hard outer covering of many animals
lac purified by heating and filtering; usually in thin orange or yellow flakes but sometimes bleached white
Shetland wool
a wool obtained from sheep of the Shetland islands
coarse beach gravel of small waterworn stones and pebbles (or a stretch of shore covered with such gravel)
(geology) sediment in which flat pebbles are uniformly tilted in the same direction
reclaimed wool fiber
shoe leather
leather used to make shoes
short-staple cotton
cotton with relatively short fibers
shot metal
an alloy that is 98% lead and 2% arsenic; used in making small shot
a tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors
the granitelike rocks that form the outermost layer of the earth's crust; rich in silicon and aluminum
material applied to the outside of a building to make it weatherproof
an earth color containing ferric oxides; used as a pigment
a pure form of finely ground silica
silica gel
a porous form of silica that is highly absorbent
a white or colorless vitreous insoluble solid (SiO2); various forms occur widely in the earth's crust as quartz or cristobalite or tridymite or lechatelierite
a salt or ester derived from silicic acid
silicic acid
a jellylike substance (hydrated silica)
any of various compounds of silicon with a more electropositive element or radical
silicon bronze
a bronze with 2-3% silicon that is resistant to corrosion
silicon carbide
an extremely hard blue-black crystalline compound (SiC) used as an abrasive and a heat refractory material; crystals of silicon carbide can be used as semiconductors
silicone resin
a polymeric silicone compound
silicone rubber
made from silicone elastomers; retains flexibility resilience and tensile strength over a wide temperature range
any of a large class of siloxanes that are unusually stable over a wide range of temperatures; used in lubricants and adhesives and coatings and synthetic rubber and electrical insulation
animal fibers produced by silkworms and other larvae that spin cocoons and by most spiders
any of a large class of compounds that have alternate silicon and oxygen atoms
mud or clay or small rocks deposited by a river or lake
a fine-grained sandstone of consolidated silt
silver bromide
a bromide that darkens when exposed to light; used in making photographic emulsions
silver chloride
a chloride used chiefly in the manufacture of photographic emulsions
silver iodide
an iodide that is used in photography, in seeding clouds to make rain, and in medicine
silver nitrate
a nitrate used in making photographic emulsions; also used in medicine as a cautery and as a topical antibacterial agent
silver solder
a solder that contains silver
a herbicide that is effective in controlling woody plants but is toxic to animals
rock that form the continuous lower layer of the earth's crust; rich in silicon and magnesium
a herbicide used to control weeds (especially among crops)
a brand of car polish
simple protein
a protein that yields only amino acids when hydrolyzed
a red ocher formerly used as a pigment
a plant fiber used for making rope
any glutinous material used to fill pores in surfaces or to stiffen fabrics
ski wax
wax used on the bottom of skis
dust consisting of a mixture of small coal fragments and coal dust and dirt that sifts out when coal is passed over a sieve
a fine-grained metamorphic rock that can be split into thin layers
thin layers of rock used for roofing
potter's clay that is thinned and used for coating or decorating ceramics
(usually plural) waste water from a kitchen or bathroom or chamber pot that has to be emptied by hand
a caustic detergent useful for removing grease; although commonly included in personal care items (shampoos and toothpastes etc.) it can irritate skin and should not be swallowed
the precipitate produced by sewage treatment
a suspension of insoluble particles (as plaster of Paris or lime or clay etc.) usually in water
partially melted snow
a grey lustrous metallic element of the rare earth group; is used in special alloys; occurs in monazite and bastnasite
a grey mineral consisting of cobalt arsenide and nickel; an important source of cobalt and nickel
smelling salts
a pungent preparation of ammonium carbonate and perfume; sniffed as a stimulant to relieve faintness
a silvery malleable metallic element that resists corrosion; used in many alloys and to coat other metals to prevent corrosion; obtained chiefly from cassiterite where it occurs as tin oxide
snake oil
(medicine) any of various liquids sold as medicine (as by a travelling medicine show) but medically worthless
snake venom
venom secreted by certain snakes
a layer of snowflakes (white crystals of frozen water) covering the ground
the charred portion of a candlewick
a soft heavy compact variety of talc having a soapy feel; used to make hearths and tabletops and ornaments
an enzyme that catalyzes the conversion of superoxide into hydrogen peroxide and oxygen
soda lime
a mixture of sodium and calcium hydroxides; absorbs liquids and gases
soda niter
(NaNO3) used especially as a fertilizer and explosive
a vitreous mineral consisting of sodium aluminum silicate and sodium chloride in crystalline form; occurs in igneous rocks
sodium bichromate
a red-orange salt used as a mordant
sodium carboxymethyl cellulose
a gummy substance that is a sodium salt of carboxymethyl cellulose; used as a thickening or emulsifying agent
sodium chlorate
a colorless salt (NaClO3) used as a weed killer and an antiseptic
sodium cyanide
a white poisonous salt (NaCN) used in electroplating
sodium fluoride
a colorless crystalline salt of sodium (NaF) used in fluoridation of water and to prevent tooth decay
sodium hydride
a flammable grey crystalline binary compound (NaH)
sodium hypochlorite
an unstable salt (NaOCl) used as a bleaching agent and disinfectant
sodium iodide
a crystalline salt used like potassium iodide
sodium nitrite
nitrite used to preserve and color food especially in meat and fish products; implicated in the formation of suspected carcinogens
sodium orthophosphate
phosphate of sodium; used as a laxative to cleanse the bowels
sodium pyrophosphate
a sodium salt of pyrophosphoric acid used as a builder in soaps and detergents
sodium silicate
a viscous glass consisting of sodium silicate in solution; used as a cement or as a protective coating and to preserve eggs
sodium sulfate
a solid white bitter salt used in manufacturing glass and paper and dyes and pharmaceuticals
sodium tripolyphosphate
a sodium salt of triphosphoric acid used as a builder in soaps and detergents
soft glass
glass having a relatively low softening point
soft solder
solder that melts at a relatively low temperature
soft water
water that is not hard (does not contain mineral salts that interfere with the formation of lather with soap)
a substance added to another to make it less hard
soil conditioner
a chemical substance used to improve the structure of the soil and increase its porosity
an alloy (usually of lead and tin) used when melted to join two metal surfaces
soldering flux
flux applied to surfaces that are to be joined by soldering; flux cleans the surfaces and results in a better bond
matter that is solid at room temperature and pressure
the dissolved matter in a solution; the component of a solution that changes its state
a homogeneous mixture of two or more substances; frequently (but not necessarily) a liquid solution
a compound formed by solvation (the combination of solvent molecules with molecules or ions of the solute)
solvating agent
an agent that converts something into a solvate
Sonora lac
resembling lac; secreted by a scale living on twigs of certain Mexican shrubs; used locally as medicine
a material that has been or is capable of being taken up by another substance by either absorption or adsorption
a material that sorbs another substance; i.e. that has the capacity or tendency to take it up by either absorption or adsorption
sorbic acid
a white crystalline carboxylic acid used as a preservative
any composition having a consistency suggestive of soup
sour mash
a mash with optimum acidity for yeast fermentation; a mixture of old and new mash; used in distilling some whiskeys
a leaven of dough in which fermentation is active; used by pioneers for making bread
powder (containing gypsum plaster and glue) that when mixed with water forms a plastic paste used to fill cracks and holes in plaster
any of various nonmetallic minerals (calcite or feldspar) that are light in color and transparent or translucent and cleavable
sparkle metal
matte that has 74 percent copper
impure zinc containing about three percent lead and other impurities (especially in the form of ingots)
sperm oil
an animal oil found in the blubber of the sperm whale
a white waxy substance from oil of the sperm whale
aromatic substances of vegetable origin used as a preservative
pig iron containing manganese; used as a deoxidizing agent and to raise the manganese content in making steel
liquid that is spilled
spray blown up from the surface of the sea
a hard glassy mineral consisting of an oxide of magnesium and aluminum; occurs in various colors that are used as gemstones
spirit gum
an adhesive solution made of gum and ether and used to attach false hair to skin
spirits of wine
rectified ethyl alcohol
a pyroxene mineral consisting of lithium aluminum silicate; a source of lithium
a porous mass of interlacing fibers that forms the internal skeleton of various marine animals and usable to absorb water or any porous rubber or cellulose product similarly used
water in small drops in the atmosphere; blown from waves or thrown up by a waterfall
a pesticide in suspension or solution; intended for spraying
the fur of a squirrel
a soft silver-white or yellowish metallic element of the alkali metal group; turns yellow in air; occurs in celestite and strontianite
a chemical that is added to a solution or mixture or suspension to maintain it in a stable or unchanging state
a tetrasaccharide found in the tubers of the Chinese artichoke
(Old Testament) one of several sweet-smelling spices used in incense
building material consisting of plaster and hair; used to cover external surfaces of temporary structure (as at an exposition) or for decoration
(microscopy) a dye or other coloring material that is used in microscopy to make structures visible
stained glass
glass that has been colored in some way; used for church windows
stand oil
a thick oil comprised of linseed, tung, or soya oils which have been heated to over 300 C
stannic chloride
a colorless caustic liquid made by treating tin with chlorine
a dark grey mineral with a metallic luster that is a source of tin
stannous fluoride
a white powder that is used to fluoridate toothpaste
staphylococcal enterotoxin
a soluble exotoxin produced by some strains of staphylococcus; a cause of food poisoning
staphylococcal enterotoxin B
a form of staphylococcal enterotoxin that has been used as an incapacitating agent in biological warfare
a natural fiber (raw cotton, wool, hemp, flax) that can be twisted to form yarn
star sapphire
a sapphire that when cut shows a starlike figure in reflected light because of its crystalline structure
a commercial preparation of starch that is used to stiffen textile fabrics in laundering
starting buffer
buffer solution at the start of a reaction
water at boiling temperature diffused in the atmosphere
steam coal
coal suitable for use under steam boilers
an ester of glycerol and stearic acid
an alloy of iron with small amounts of carbon; widely used in construction; mechanical properties can be varied over a wide range
steel wool
a mass of woven steel fibers used as an abrasive
a very hard alloy of cobalt and chromium with cobalt as the principal ingredient; used to make cutting tools and for surfaces subject to heavy wear
a chromogen formed in the intestine from the breakdown of bilirubin; yields urobilins on oxidation; some is excreted in the feces and some is resorbed and excreted in bile or urine
sterling silver
a silver alloy with no more than 7.5% copper
a chemical substance that causes sneezing and coughing and crying
any of several fat-soluble organic compounds having as a basis 17 carbon atoms in four rings; many have important physiological effects
steroid alcohol
any of a group of natural steroid alcohols derived from plants or animals; they are waxy insoluble substances
a soft grey mineral; the chief ore of antimony
stick lac
lac in its natural state as scraped off twigs and dried
sticks and stone
a general term for building materials
sticky end
an end of DNA in which one strand of the double helix extends a few units beyond the other
material used for stiffening something
plant fiber used e.g. for making baskets and hats or as fodder
a coarse yellow cardboard made of straw pulp
an enzyme produced by some hemolytic strains of streptococcus that dissolves fibrinous secretions from infections; used medicinally (often in combination with streptokinase)
an enzyme produced by some strains of streptococcus that can liquefy blood clots by converting plasminogen to plasmin; used medicinally in some cases of myocardial infarction and pulmonary embolism
any of several hemolysins derived from strains of streptococcus
a tough piece of fiber in vegetables, meat, or other food (especially the tough fibers connecting the two halves of a bean pod)
a chemical compound used to remove paint or varnish
a mineral consisting of strontium carbonate
strontium 90
a radioactive isotope of strontium (with the mass number 90) that is present in the fallout from nuclear explosions; can be assimilated like calcium into bones
a bitter and very toxic glycoside derived from plants of the genus Strophanthus; in moderate doses it is a cardiac stimulant but in larger doses it is a powerful poison; used in Africa as an arrow poison
structural iron
iron that has been cast or worked in structural shapes
structural steel
a strong steel that is rolled into shapes that are used in construction
an alkaloid plant toxin extracted chiefly from nux vomica; formerly used as a stimulant
a plaster now made mostly from Portland cement and sand and lime; applied while soft to cover exterior walls or surfaces
a light resilient foam of polystyrene
the product of vaporization of a solid
the layer of soil between the topsoil and bedrock
material of a particular kind or constitution
the substance that is acted upon by an enzyme or ferment
succinic acid
a dicarboxylic acid (C4H6O4) active in metabolic processes
leather with a napped surface
sulfanilic acid
a crystalline acid made from aniline and used as a dye
a salt or ester of sulphuric acid
a compound of sulphur and some other element that is more electropositive
a salt of sulphonic acid
sulfonic acid
an acid derived from sulphuric acid
sulfur dioxide
a colorless toxic gas (SO2) that occurs in the gases from volcanoes; used in many manufacturing processes and present in industrial emissions; causes acid rain
sulfur hexafluoride
a colorless gas that is soluble in alcohol and ether; a powerful greenhouse gas widely used in the electrical utility industry
sulfur oxide
any of several oxides of sulphur
a metallic oxide containing the univalent anion O2-
the univalent anion O2-
surface soil
the layer of soil on the surface
surface-active agent
a chemical agent capable of reducing the surface tension of a liquid in which it is dissolved
surgical spirit
methylated spirit used in the practice of medicine (especially for cleansing the skin before injections or before surgery)
a mixture in which fine particles are suspended in a fluid where they are supported by buoyancy
Swedish iron
wrought iron of high purity made in Sweden
swinging chad
a chad that is incompletely removed and still attached at two corners
a mineral consisting of native potassium chloride; an important ore of potassium that is found in sedimentary beds
synthetic resin
a resin having a polymeric structure; especially a resin in the raw state; used chiefly in plastics
a compound made artificially by chemical reactions
(physical chemistry) a sample of matter in which substances in different phases are in equilibrium
one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
a base found in DNA (but not in RNA) and derived from pyrimidine; pairs with adenine
a hard grey lustrous metallic element that is highly resistant to corrosion; occurs in niobite and fergusonite and tantalite
a basic or basalt glass
a variety of chert containing magnetite and hematite; mined as a low-grade iron ore
a fine grained mineral having a soft soapy feel and consisting of hydrated magnesium silicate; used in a variety of products including talcum powder
tall oil
an oil derived from wood pulp and used in making soaps or lubricants
obtained from suet and used in making soap, candles and lubricants
tallow oil
an animal oil obtained by pressing tallow; used as a lubricant
an alloy of copper and zinc (and sometimes arsenic) used to imitate gold in cheap jewelry and for gilding
tannic acid
any of various complex phenolic substances of plant origin; used in tanning and in medicine
a mineral consisting of tantalum oxide of iron and manganese that occurs with niobite or in coarse granite; an ore of tantalum
a paving material of tar and broken stone; mixed in a factory and shaped during paving
tartaric acid
an acid found in many fruits; used in soft drinks and confectionery and baking powder
a salt or ester of tartaric acid
a colorless crystalline substance obtained from the bile of mammals
a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite
a crystalline metallic element not found in nature; occurs as one of the fission products of uranium
a heavy colorless highly toxic liquid used as a solvent to clean electronic components and for dry cleaning and as a fumigant; causes cancer and liver and lung damage
a brittle silver-white metalloid element that is related to selenium and sulfur; it is used in alloys and as a semiconductor; occurs mainly as tellurides in ores of copper and nickel and silver and gold
a material used to coat cooking utensils and in industrial applications where sticking is to be avoided
thought to derive from meteorites
any binary compound of tellurium with other more electropositive elements
an enzyme in eukaryotic cells that can add telomeres to the ends of chromosomes after they divide
a substance (as the plant enzyme papain) applied to meat to make it tender
terbium metal
a separate group of related lanthanides, including terbium, europium, gadolinium, and sometimes dysprosium
an unsaturated hydrocarbon obtained from plants
terra alba
finely pulverized gypsum used especially as a pigment
a potent androgenic hormone produced chiefly by the testes; responsible for the development of male secondary sex characteristics
tetanus antitoxin
antitoxin given for short-term immunization against tetanus in cases of possible exposure to the tetanus bacillus
tetanus immune globulin
sterile solution of globulins derived from the blood plasma of a person who has been immunized for tetanus; provides short-term immunization against tetanus in cases of possible exposure to the tetanus bacillus
tetrabasic acid
an acid containing four replaceable hydrogen atoms per molecule
any compound that contains four chlorine atoms per molecule
a flammable gaseous fluorocarbon used in making plastics (polytetrafluoroethylene resins)
any halide containing four halogen atoms in its molecules
any of a variety of carbohydrates that yield four monosaccharide molecules on complete hydrolysis
a powerful neurotoxin found in the ovaries of pufferfish
any monosaccharide sugar containing four atoms of carbon per molecule
an oxide containing four atoms of oxygen in the molecule
a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
plant stalks used as roofing material
a material that softens when heated and hardens again when cooled
thermosetting compositions
a material that hardens when heated and cannot be remolded
a compound made up of a ring of four carbon atoms and one sulfur atom and one nitrogen atom
any material used to thicken
a salt of thiocyanic acid; formed when alkaline cyanides are fused with sulfur
thiocyanic acid
an unstable acid that can be obtained by distilling a thiocyanate salt
depresses the function of the thyroid gland
a radioactive mineral consisting of thorium silicate; it is a source of thorium that is found in coarse granite
a mineral consisting of scandium yttrium silicate; a source of scandium
a colorless crystalline amino acid found in protein; occurs in the hydrolysates of certain proteins; an essential component of human nutrition
an enzyme that acts on fibrinogen in blood causing it to clot
thyme camphor
a colorless crystalline solid used in perfume or preserving biological specimens or in embalming or medically as a fungicide or antiseptic
an iodine containing protein that is obtained from the thyroid gland and exhibits the general properties of the globulins
a phenolic amino acid of which thyroxine is a derivative
a preparation made from iodinated protein and having an action similar to thyroxine
a light strong grey lustrous corrosion-resistant metallic element used in strong lightweight alloys (as for airplane parts); the main sources are rutile and ilmenite
ticker tape
a continuous thin ribbon of paper on which stock quotes are written
Tiffany glass
a kind of opalescent colored glass that was used in the early 1900s for stained-glass windows and lamps
a substance that colors or dyes
a soft thin (usually translucent) paper
a white powder used as a pigment for its high covering power and durability
titanic acid
a white weak acid that is a hydrated form of titanium dioxide
a soft grey malleable metallic element that resembles tin but discolors on exposure to air; it is highly toxic and is used in rodent and insect poisons; occurs in zinc blende and some iron ores
a soft silvery metallic element of the rare earth group; isotope 170 emits X-rays and is used in small portable X-ray machines; it occurs in monazite and apatite and xenotime
a proinflammatory cytokine that is produced by white blood cells (monocytes and macrophages); has an antineoplastic effect but causes inflammation (as in rheumatoid arthritis)
toilet roll
a roll of toilet paper
toluic acid
an isomeric acid derived from toluene
a black or colored powder used in a printer to develop a xerographic image
a solution containing chemicals that can change the color of a photographic print
tool steel
alloy steel that is suitable for making tools; is hard and tough and can retain a cutting edge
top fermenting yeast
brewer's yeast used in top fermentation of ale
a mineral (fluosilicate of aluminum) that occurs in crystals of various colors and is used as a gemstone
the mottled horny substance of the shell of some turtles
a mineral that is a complex borosilicate and hydroxide of aluminum containing iron and magnesium and calcium and lithium and sodium; it is usually black but occurs in transparent colored forms that are used as gemstones
town gas
coal gas manufactured for domestic and industrial use
toxic industrial waste
poisonous waste materials; can cause injury (especially by chemical means)
a poisonous substance produced during the metabolism and growth of certain microorganisms and some higher plant and animal species
toxin antitoxin
a mixture of toxin and antitoxin used to immunize against a disease
trace element
an element that occurs at very small quantities in the body but is nonetheless important for many biological processes
tracing paper
a semitransparent paper that is used for tracing drawings
a gum used in pharmacy, adhesives, and textile printing
train oil
a white to brown oil obtained from whale blubber; formerly used as an illuminant
trans fatty acid
a fatty acid that has been produced by hydrogenating an unsaturated fatty acid (and so changing its shape); found in processed foods such as margarine and fried foods and puddings and commercially baked goods and partially hydrogenated vegetable oils
any of the artificially produced elements with atomic numbers greater than 103
transfer paper
a paper that is coated with a preparation for transferring a design to another surface
any of various enzymes that move a chemical group from one compound to another compound
translucent substance
a material having the property of admitting light diffusely; a partly transparent material
transparent gem
a gemstone having the property of transmitting light without serious diffusion
a substance that transudes
transuranic element
any element having an atomic number greater than 92 (which is the atomic number of uranium); all are radioactive
a white or pale green mineral (calcium magnesium silicate) of the amphibole group used as a form of asbestos
hormone released by the hypothalamus that controls the release of thyroid-stimulating hormone from the anterior pituitary
a chad that is incompletely removed and still attached at three corners
thyronine with three iodine atoms added
any of three isomeric compounds having three carbon and three nitrogen atoms in a six-membered ring
tribasic acid
an acid containing three replaceable hydrogen atoms per molecule
tribasic sodium phosphate
the tertiary phosphate of sodium used as a builder in soaps and detergents
a bitter oily triglyceride of butyric acid; a form of butyrin
trichloracetic acid
a strong acid made by chlorinating acetic acid
any compound containing three chlorine atoms in each molecule
a mineral form of silica
glyceride occurring naturally in animal and vegetable tissues; it consists of three individual fatty acids bound together in a single large molecule; an important energy source forming much of the fat stored by the body
a polymer (or a molecule of a polymer) consisting of three identical monomers
any monosaccharide sugar containing three atoms of carbon per molecule
an oxide containing three atoms of oxygen in the molecule
a pyridine ring with three phosphorus groups
triphosphopyridine nucleotide
a coenzyme of several enzymes
triphosphoric acid
an acid that is a partial anhydride of three molecules of phosphoric acid; known chiefly in the form of its salts and esters
any of a variety of carbohydrates that yield three monosaccharide molecules on complete hydrolysis
a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms
an enzyme of pancreatic origin; catalyzes the hydrolysis of proteins to smaller polypeptide units
inactive precursor of trypsin; a substance secreted by the pancreas and converted to active trypsin by enterokinase in the small intestine
an amino acid that occurs in proteins; is essential for growth and normal metabolism; a precursor of niacin
anterior pituitary hormone that stimulates the function of the thyroid gland
a sterile liquid containing a purified protein derivative of the tuberculosis bacterium; used in the diagnosis of tuberculosis
hard volcanic rock composed of compacted volcanic ash
an antacid
tuna oil
an oil obtained from tuna
tundra soil
a black mucky soil with a frozen subsoil that is characteristic of Arctic and subarctic regions
a salt of tungstic acid
tungsten steel
a very hard heat-resistant steel containing tungsten
tungstic acid
an oxyacid of tungsten (often polymeric in nature) formed by neutralizing alkaline tungstate solutions
Turkish tobacco
a dark aromatic tobacco of eastern Europe that is used in cigarettes
a blue to grey green mineral consisting of copper aluminum phosphate
(mineralogy) two interwoven crystals that are mirror images on each other
type metal
an alloy of tin and lead and antimony used to make printing type
typewriter paper
writing paper suitable for use in a typewriter
amino acid derived from tyrosine; has a sympathomimetic action; found in chocolate and cola drinks and ripe cheese and beer
Tyrian purple
a red-purple to deep purple dye obtained from snails or made synthetically
an amino acid found in most proteins; a precursor of several hormones
a base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine
a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
an impure mixture of uranium oxides obtained during the processing of uranium ore
blue pigment made of powdered lapis lazuli
an earth pigment
undecylenic acid
an acid that is a component of perspiration
the material removed by a cut made underneath
unleaded gasoline
gasoline that has not been treated with a lead compound
a radioactive transuranic element which has been synthesized
unsaturated fatty acid
a fatty acid whose carbon chain can absorb additional hydrogen atoms
uranium 235
a uranium isotope with mass number 235; capable of sustaining chain reactions
uranium 238
the commonest isotope of uranium; it is not fissionable but when irradiated with neutrons it produces fissionable plutonium 239
uranium ore
any ore from which uranium can be extracted
uranyl nitrate
a yellow salt obtained by the reaction of uranium salts with nitric acid
uranyl oxalate
a salt obtained by the reaction of uranium salts with oxalic acid
the bivalent radical UO2 which forms salts with acids
a salt of uric acid
urea-formaldehyde resin
a clear thermosetting resin made from urea and formaldehyde and used in electrical fittings, adhesives, and finishes
an enzyme that catalyzes the hydrolysis of urea into carbon dioxide and ammonia; is present in intestinal bacteria
an ester of carbamic acid
uric acid
a white tasteless odorless crystalline product of protein metabolism; found in the blood and urine
brown bile pigment formed from urobilinogens and found in feces and in small amounts in urine
a radioactive transuranic element
a radioactive transuranic element
a radioactive transuranic element
a radioactive transuranic element
a radioactive transuranic element
a soft silvery white toxic metallic element used in steel alloys; it occurs in several complex minerals including carnotite and vanadinite
vaginal discharge
discharge of secretions from the cervical glands of the vagina; normally clear or white
an essential amino acid found in proteins; important for growth in children and nitrogen balance in adults
a salt or ester of vanadic acid; an anion containing pentavalent vanadium
vanadic acid
any of various oxyacids of vanadium; known mostly in the form of its salts
a mineral consisting of chloride and vanadate of lead; a source of vanadium
vanadium steel
steel alloyed with vanadium for greater strength and high-temperature stability
a visible suspension in the air of particles of some substance
vat color
a water-insoluble dye that is applied by reducing the dye to an alkaline form, applying the dye, then regenerating the insoluble dye by oxidation in the material; used for dyeing cotton
vegetable matter
matter produced by plants or growing in the manner of a plant
vegetable tallow
a waxy fat obtained from certain plants (e.g. bayberry) and used as tallow
vegetable wax
a waxy substance obtained from plants (especially from the trunks of certain palms)
any substance that facilitates the use of a drug or pigment or other material that is mixed with it
a heavy creamy-colored paper resembling parchment
fine parchment prepared from the skin of a young animal e.g. a calf or lamb
toxin secreted by animals; secreted by certain snakes and poisonous insects (e.g., spiders and scorpions)
verd antique
a dark green impure marble
any of a group of yellow or brown hydrous silicate minerals having a micaceous structure
a white cheeselike protective material that covers the skin of a fetus
a chemical agent that causes blistering (especially mustard gas)
the wool of the vicuna
dilute acetic acid
shiny and tough and flexible plastic; used especially for floor coverings
a univalent chemical radical derived from ethylene
any of various vinyl resins
virgin wool
wool not used before; wool not processed or woven before
an agent (physical or chemical) that inactivates or destroys viruses
any of a group of organic substances essential in small quantities to normal metabolism
vitamin A
any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
vitamin A1
an unsaturated alcohol that occurs in marine fish-liver oils and is synthesized biologically from carotene
vitamin A2
a viscous alcohol that is less active in mammals than is vitamin A1
vitamin B1
a B vitamin that prevents beriberi; maintains appetite and growth
vitamin B12
a B vitamin that is used to treat pernicious anemia
vitamin B2
a B vitamin that prevents skin lesions and weight loss
vitamin B6
a B vitamin that is essential for metabolism of amino acids and starch
vitamin Bc
a B vitamin that is essential for cell growth and reproduction
vitamin C
a vitamin found in fresh fruits (especially citrus fruits) and vegetables; prevents scurvy
vitamin D
a fat-soluble vitamin that prevents rickets
vitamin E
a fat-soluble vitamin that is essential for normal reproduction; an important antioxidant that neutralizes free radicals in the body
vitamin H
a B vitamin that aids in body growth
vitamin K
a fat-soluble vitamin that helps in the clotting of blood
vitamin K1
a form of vitamin K
vitamin K3
a form of vitamin K
vitamin P
a vitamin that maintains the resistance of cell and capillary walls to permeation
a vitrified substance; the glassy result of being vitrified
large lipoproteins rich in triglycerides; VLDLs circulate through the blood giving up their triglycerides to fat and muscle tissue until the VLDL remnants are modified and converted into LDL
a volatile substance; a substance that changes readily from solid or liquid to a vapor
volcanic glass
a kind of natural glass produced when molten lava cools very rapidly
volcanic rock
extrusive igneous rock solidified near or on the surface of the Earth
VX gas
a highly lethal nerve agent used in chemical warfare; a toxic liquid that penetrates the skin or lungs to disrupt the nervous system and stop respiration; in combat VX gas is deployed by detonating a container over the target area and can persist in the environment up to several weeks after release
a heavy grey-white metallic element; the pure form is used mainly in electrical applications; it is found in several ores including wolframite and scheelite
a small mass of soft material
a small adhesive disk of paste; used to seal letters
a decorative paper for the walls of rooms
wash leather
piece of chamois used for cleaning and polishing
waste paper
paper discarded after use
any materials unused and rejected as worthless or unwanted
once thought to be one of four elements composing the universe (Empedocles)
water gas
a mixture of hydrogen and carbon monoxide with small amounts of other gases; made by blowing steam over hot coke or coal
water of crystallisation
the water present in hydrated compounds
water sapphire
a deep blue cordierite often used as a gemstone
water softener
a substance (such as sodium chloride) that lessens the hardness of water by replacing calcium and magnesium ions with sodium ions and so gives the water more efficient sudsing power
water vapor
water in a vaporous form diffused in the atmosphere but below boiling temperature
water-soluble vitamin
any vitamin that is soluble in water
water-soluble pigment
wattle and daub
building material consisting of interwoven rods and twigs covered with clay
any of various substances of either mineral origin or plant or animal origin; they are solid at normal temperatures and insoluble in water
wax paper
paper that has been waterproofed by treatment with wax or paraffin
weapons plutonium
plutonium 239 that is recovered when nuclear weapons are disassembled; it is stored in plutonium pits
whit leather
a leather that has been treated with alum and/or salt
white gold
a pale alloy of gold usually with platinum or nickel or palladium
white vitriol
a colorless water-soluble powder; used as a mordant or to preserve wood or for the electrodeposition of zinc
slender flexible branches or twigs (especially of willow or some canes); used for wickerwork
a dark meadow soil rich in organic material; developed through poor drainage in humid grassy or sedge regions
Windsor green
a light chrome green pigment
wire glass
a glass that contains a layer of wire netting in it
a blue dyestuff obtained from the woad plant
a white or greyish mineral typically found in metamorphic limestone; a silicate of calcium
the hard fibrous lignified substance under the bark of trees
wood pulp
wood that has been ground to a pulp; used in making cellulose products (as rayon or paper)
wood sugar
a sugar extracted from wood or straw; used in foods for diabetics
wood tar
any tar obtained by the destructive distillation of wood
Wood's metal
a fusible alloy that is half bismuth plus lead, tin, and cadmium; melts at about 160 degrees Fahrenheit
fiber sheared from animals (such as sheep) and twisted into yarn for weaving
wool oil
any oil used to oil wool before spinning
cylindrical mass of earth voided by a burrowing earthworm or lugworm
wove paper
writing paper having a very faint mesh pattern
wrapping paper
a tough paper used for wrapping
writing ink
any permanent or washable ink used with pens
writing paper
paper material made into thin sheets that are sized to take ink; used for writing correspondence and manuscripts
wrought iron
iron having a low carbon content that is tough and malleable and so can be forged and welded
a yellow to orange or brown mineral used as a molybdenum ore
a brownish-black mineral consisting of zinc sulfide
a salt or ester of xanthic acid
xanthic acid
any of a class of unstable organic acids containing sulphur
crystalline oxidation product of the metabolism of nucleoproteins; precursor of uric acid; found in many organs and in urine
a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
a brown-to-yellow mineral that is a phosphate of yttrium in crystalline form
a colorless flammable volatile liquid hydrocarbon used as a solvent
a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys
a soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime
yellow ocher
pigment consisting of a limonite mixed with clay and silica
(cosmology) the original matter that (according to the big bang theory) existed before the formation of the chemical elements
Yule log
large log traditionally burned at Christmas
Zanzibar copal
a hard copal derived from an African tree
yellow carotenoid (isomeric with lutein and occurs widely with it) that is the main pigment in yellow Indian corn
any of a family of glassy minerals analogous to feldspar containing hydrated aluminum silicates of calcium or sodium or potassium; formed in cavities in lava flows and in plutonic rocks
zinc cadmium sulfide
cadmium sulfide containing zinc
zinc sulfide
a yellow to white crystalline fluorescent compound that occurs naturally as sphalerite or wurtzite and is used as a luminous pigment
a steel grey metallic mineral (a sulphide of lead and antimony)
a mica containing iron and lithium
a common mineral occurring in small crystals; chief source of zirconium; used as a refractory when opaque and as a gem when transparent
a white crystalline oxide; used in refractories and in insulation and abrasives and enamels and glazes
a bluish-white lustrous metallic element; brittle at ordinary temperatures but malleable when heated; used in a wide variety of alloys and in galvanizing iron; it occurs naturally as zinc sulphide in zinc blende
a lustrous grey strong metallic element resembling titanium; it is used in nuclear reactors as a neutron absorber; it occurs in baddeleyite but is obtained chiefly from zircon
a complex of enzymes that cause glycolysis; originally found in yeast but also present in higher organisms