indispensable

Adjective
  1. Not to be dispensed with;
    Essential (synset 300906890)
    "foods indispensable to good nutrition"
    also: necessary - absolutely essential
    tells us about: dispensability, dispensableness - the quality possessed by something that you can get along without
    similar to: critical, vital - urgently needed; absolutely necessary
  2. Absolutely necessary;
    Vitally necessary (synset 301584714)
    "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"
    similar to: necessary - absolutely essential
    same as: essential
  3. Unavoidable (synset 300852532)
    "the routine but indispensable ceremonies of state"
    similar to: obligatory - morally or legally constraining or binding

Found on Word Lists

Other Searches