Biretta (Ital. berretta; dim. of birrus, 'a hooded cloak'), a square cap worn by the clergy of the Roman Catholic Church, and by some ritualists in the Anglican Church. That of priests is black, of bishops purple, of cardinals red. Originally round, its present form, with straight, erect edges, and a tuft or button on the crown, dates only from the 17th century; but the low head-covering of English bishops was known as the birrettum as early as the 13th century.
