Berretta,
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. [1913 Webster]