Origin: 1590–1600; < It berretta, fem. var. of berretto < OPr berret < ML birrettum cap, equiv. to LL birr(us) birrus+ -ettum-et; appar. by the development: hooded cloak > hood > cap; cf. ML (ca. 800) byrrus short hood (cuculla brevis)
be·ret·ta or ber·ret·ta (bə-rět'ə) n. Variants of biretta.
bi·ret·ta also be·ret·ta or ber·ret·ta (bə-rět'ə) n.
Ecclesiastical A stiff square cap with three or four ridges across the crown. Birettas are worn especially by Roman Catholic clergy and are black for priests, purple for bishops, and red for cardinals.
[Italian berretta, from Old Provençal berret, cap, from Late Latin birrus, hooded cloak, probably of Celtic origin.]
square cap worn by Catholic clergy, 1598, from It. beretta, from L.L. birrus, birrum "large cloak with hood, perhaps of Gaulish origin, or from Gk. pyrros "flame-colored, yellow."