Meaning of caddisfly

cad•dis•fly

Pronunciation: (kad'is-flī"), [key]
— pl. -flies.
  1. any of numerous aquatic insects constituting the order Trichoptera, having two pairs of membranous, often hairy wings and superficially resembling moths.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.