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cad·dis·wormor caddis worm (kăd′ĭs-wûrm′)
The aquatic wormlike larva of a caddisfly, enclosed in a cylindrical case covered with grains of sand, bits of wood or shell, or other debris.
(Animals) the aquatic larva of a caddis fly, which constructs a protective case around itself made of silk, sand, stones, etc. Also called: caseworm or strawworm
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.
[1615–25; caddis (perhaps pl., taken as singular, of caddy, diminutive of cad larva, ghost) + worm]