from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The fact, quality, or state of being certain, especially:
  • noun Inevitability.
  • noun The quality of being established as true.
  • noun Confidence; assurance.
  • noun Something that is clearly established or assured.

from The Century Dictionary.

  • noun The quality or fact of being certain, fixed, determinate, or sure; the possession, as by a judgment or proposition, of certain marks which place it in the class of true propositions; exemption from failure or liability to fail; infallibility; inevitability: as, the certainty of an event, or of the success of a remedy.
  • noun A clearly established fact, truth, or state; that which is positively ascertained, demonstrated, or intuitively known, or which cannot be questioned.
  • noun That which is sure to be or occur; an assured event or result; an unerring forecast.
  • noun Full assurance of mind; exemption from doubt; certitude.
  • noun Same as certain, 3.

from the GNU version of the Collaborative International Dictionary of English.

  • noun The quality, state, or condition, of being certain.
  • noun A fact or truth unquestionable established.
  • noun (Law) Clearness; freedom from ambiguity; lucidity.
  • noun certainly.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun The state of being certain.
  • noun An instance of being certain.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun the state of being certain
  • noun something that is certain


from Wiktionary, Creative Commons Attribution/Share-Alike License

Middle English surety, from Anglo-Norman certeinté, from Old French certeineté, from Vulgar Latin *certanitas, from Latin certus


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