/ Dictionary / Index B birrus: Meaning and Definition of Find definitions for: bir•rus Pronunciation: (bir'us), [key] — pl. bir•ri a hooded cloak of coarse wool, a common article of apparel in the later Roman Empire. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. birretta birse Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language