/ Dictionary / Index N ninety-nine: Meaning and Definition of Find definitions for: nine•ty-nine Pronunciation: (nīn'tē-nīn'), [key] — n. a cardinal number, 90 plus 9. a symbol for this number, as 99 or XCIX. a set of this many persons or things. —adj. amounting to 99 in number. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ninety-nine (Thesaurus) ninety-fourth ninety-ninth Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language