caterpillar

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The wormlike larva of a butterfly or moth.
2. n. Any of various insect larvae similar to those of the butterfly or moth.

Century Dictionary and Cyclopedia

1. n. Properly, the larva of a lepidopterous insect, but also applied to the larvæ of other insects, such as members of the family Tenthredinidœ, or saw-flies. Caterpillars are produced immediately from the egg; they are furnished with three pairs of true feet and a number of fleshy abdominal legs named prolegs, and have the shape and appearance of a worm. The old idea of Swammerdam that the pupa and imago are already concealed under the skin of the caterpillar is only partially founded in truth. The pupal skin is formed from the hypodermis of the larva, and the muscles contract and change its form. The larval skin is then thrown off, and the insect remains quiescent for some time, the image or perfect insect forming beneath the pupal envelop. Caterpillars generally feed on leaves or succulent vegetables, and are sometimes very destructive. See larva.
2. n. A cockchafer.
3. n. An envious person who does mischief without provocation.
4. n. One who preys upon the substance of another; an extortioner.
5. n. The popular name of plants of the genus Scorpiurus.
6. n. The larva of an Australian lymantriid moth, Teara melanosticta, which forms in columns like the European Cnethocampa processionea.

Wiktionary

1. n. The larva of a butterfly or moth; leafworm.
2. n. A vehicle with a caterpillar track; a crawler.

GNU Webster's 1913

1. n. (Zoöl.) The larval state of a butterfly or any lepidopterous insect; sometimes, but less commonly, the larval state of other insects, as the sawflies, which are also called false caterpillars. The true caterpillars have three pairs of true legs, and several pairs of abdominal fleshy legs (prolegs) armed with hooks. Some are hairy, others naked. They usually feed on leaves, fruit, and succulent vegetables, being often very destructive, Many of them are popularly called worms, as the cutworm, cankerworm, army worm, cotton worm, silkworm.
2. n. (Bot.) A plant of the genus Scorpiurus, with pods resembling caterpillars.

WordNet 3.0

1. n. a large tracked vehicle that is propelled by two endless metal belts; frequently used for moving earth in construction and farm work
2. n. a wormlike and often brightly colored and hairy or spiny larva of a butterfly or moth