monotone

Adjective
  1. Of a sequence or function;
    Consistently increasing and never decreasing or consistently decreasing and never increasing in value (synset 301551387)
    referred to in: math, mathematics, maths - a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement
    similar to:
    same as: monotonic
  2. Sounded or spoken in a tone unvarying in pitch (synset 301545995)
    "the owl's faint monotonous hooting"
    similar to: unmodulated - characterized by lack of variation in pitch, tone, or volume
    same as: flat, monotonic, monotonous
Noun
  1. An unchanging intonation (synset 107098752)
    is a type of: intonation, modulation, pitch contour - rise and fall of the voice pitch
    same as: drone, droning
  2. A single tone repeated with different words or different rhythms (especially in rendering liturgical texts) (synset 107098939)
    is a type of: musical note, note, tone - a notation representing the pitch and duration of a musical sound

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