1540s, "long free gown," from center French casaque "long coating" (16c.), probably ultimately from Turkish quzzak "nomad, adventurer," (the source of Cossack), from their typical riding-coat. Or simply from Arabic kazagand, from Persian kazhagand "padded coating," from kazh "raw silk" + agand "stuffed." Chiefly a soldier's cloak 16c.-17c.; ecclesiastical use is from 1660s.
a black garment achieving right down to the legs; donned by priests or choristers
- an extended exterior apparel formerly donned by men and women, as well as by troops as part of their uniform.
- A garment resembling a lengthy frock coat worn by the clergy of certain churches when officiating, by other individuals as the usually outer apparel.
AUGUSTINIAN CANONS, a religious order in the Roman Catholic Church, called also Austin Canons, Canons Regular, and in England Black Canons, because their cassock and mantle were black, though they wore a white surplice: elsewhere the colour of the habit varied considerably.