MOTH, in entomology, any lepidopterous insect belonging to the division Heterocera, as distinguished from the Rhopalocera, or butterflies; formerly confined to the small nocturnal insect (belonging to the genus Tinea), which breeds in fur, clothes, &c. (see Lepidoptera). The word in O. Eng. is moþþe, and corresponds to Ger. Motte.