/ Dictionary / Index B biretta: Meaning and Definition of Find definitions for: bi•ret•ta Pronunciation: (bu-ret'u), [key] — n. a stiff square cap with three or four upright projecting pieces extending from the center of the top to the edge, worn by ecclesiastics. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: biretta (Thesaurus) bireme biri Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language