ˈkadə̇ˌswərm, -wə̄m noun
Etymology: probably alteration of obsolete cadworm, alteration of codworm
: the wormlike aquatic larva of a caddis fly that is often used as bait and lives in and carries around a cylindrical sometimes spiral case of silk covered externally with pieces of shell, fine gravel, wood, or straw
[s]caddiswo.jpg[/s]