Definition of


  1. (adj, all) exercising or taking care great enough to bring assurance
    be sure to lock the doors
  2. (adj, all) established beyond doubt or question; definitely known
    it is certain that they were on the bus
    his fate is certain
    the date for the invasion is certain
  3. (adj, all) having or feeling no doubt or uncertainty; confident and assured
    was sure (or certain) she had seen it
    was very sure in his beliefs
    sure of her friends
  4. (adj, all) certain to occur; destined or inevitable
    his fate is certain
    In this life nothing is certain but death and taxes
    he faced certain death
    sudden but sure regret
    he is sure to win
  5. (adj, all) definite but not specified or identified
    to a certain degree
    certain breeds do not make good pets
    certain members have not paid their dues
    a certain popular teacher
    a certain Mrs. Jones
  6. (adj, all) reliable in operation or effect
    a sure way to distinguish the two
    wood dust is a sure sign of termites
  7. (adj, all) established irrevocably

via WordNet, Princeton University

Synonyms of Certain

sealed, sure

Antonyms of Certain


Origin of the word Certain

  1. c.1300, "determined, fixed," from O.Fr. certain, from V.L. *certanus, from L. certus "sure, fixed," originally a variant pp. of cernere "to distinguish, decide," originally "to sift, separate" (see crisis). Certainer, certainest were common to c.1750, but have fallen from proper use for some reason. more

via Online Etymology Dictionary, ©2001 Douglas Harper

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