Origin: 1570–80; prob. < MF cadis kind of woolen cloth < OPr < Catalon cadirs, of obscure orig; ME cadace, cadas material for padding doublets (< AF) is appar. a distinct word
the aquatic larva of a caddisfly, having an armored head and a pair of abdominal hooks, and typically living in a case built from sand or plant debris.
cad·dis also cad·dice (kād'ĭs) n. A coarse woolen fabric, yarn, or ribbon binding.
[Probably from Middle English cadace, cotton wool (from Anglo-Norman, from Old Provençal cadarz) and from French cadis, woolen cloth (from Old Provençal).]