/ Dictionary / Index C certainty: Meaning and Definition of Find definitions for: cer•tain•ty Pronunciation: (sûr'tn-tē), [key] — pl. -ties. the state of being certain. something certain; an assured fact. certainly; without a doubt: I suspect it, but I don't know it for a certainty. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: certainty (Thesaurus) certainly certes Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language