Ber*ret"ta (&?;), n. [It., fr. LL. birrettum, berretum, a cap, dim. of L. birrus, birrum, a cloak to keep off rain, cf. Gr. &?; tawny, red: cf. Sp. birreta, Pg. barrete, and E. Barret.] A square cap worn by ecclesiastics of the Roman Catholic Church. A cardinal's berretta is scarlet; that worn by other clerics is black, except that a bishop's is lined with green. [Also spelt beretta, biretta, etc.]