/ Dictionary / Index T twenty-one: Meaning and Definition of Find definitions for: twen•ty-one Pronunciation: (twen'tē-wun', twun'-), [key] — n. a cardinal number, 20 plus 1. a symbol for this number, as 21 or XXI. a set of this many persons or things. Also calleda gambling game at cards, in which the object is to obtain from the dealer cards whose values add up to, or close to, 21 but which do not exceed it. —adj. amounting to 21 in number. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: twenty-one (Thesaurus) twenty-ninth twenty questions Related Content Daily Word Quiz: cur Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language