Oxford Advanced American Dictionary

Definition of caterpillar noun from the Oxford Advanced Learner's Dictionary

caterpillar

noun
caterpillar pronunciation English ˈkætəpɪlə(r) caterpillar pronunciation American ˈkætərpɪlər
 
a small creature like a worm with legs, that develops into a butterfly or moth (= flying insects with large, sometimes brightly coloured, wings). Caterpillars eat the leaves of plants.