caterpillar UK /ˈkætəˌpɪlə/US /ˈkætɚˌpɪlɚ/noun 4verb 1forms 3 noun4 •The larva of a butterfly or moth; leafworm.The bird just ate that green caterpillar. •A vehicle with a caterpillar track; a crawler. •A set of subtrees of a tree. •(no longer used) A rapacious, extortionate person preying upon the community.Bristow Castle, which they say is held / By Busbie, Bagot, and their Complices, / The Caterpillers of the Commonwealth, / Which I haue sworne to weed, and plucke away. — 1595 verb1 •To move along slowly, drawing one's body up, in the manner of a caterpillar. formscaterpillared · caterpillaring · caterpillars