What is "cankerworm"

Dropworm \Drop"worm`\ (dr[o^]p"w[^u]rm`), n. (Zo["o]l.) The larva of any geometrid moth, which drops from trees by means of a thread of silk, as the cankerworm or inchworm. See inchworm and geometrid.

Caterpillar \Cat"er*pil`lar\, n. [OE. catyrpel, corrupted fr. OF. chatepelouse, or cate pelue, fr. chate, F. chatte, she-cat, fem. of chat, L. catus + L. pilosus hairy, or F. pelu hairy, fr. L. pilus hair. See Cat, and Pile hair.]

1. (Zo["o]l.) 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. (Bot.) A plant of the genus Scorpiurus, with pods resembling caterpillars.

   Caterpillar catcher, or Caterpillar eater (Zo["o]l.), a bird belonging to the family of Shrikes, which feeds on caterpillars. The name is also given to several other birds.

   Caterpillar hunter (Zo["o]l.), any species of beetles of the genus Callosoma and other allied genera of the family Carabid[ae] which feed habitually upon caterpillars.

n. 1 Either of two caterpillars, the larvae of geometrid moths, that are destructive to fruit, buds and leaf. 2 (context figurative English) A corrupting or destructive force.

n. green caterpillar of a geometrid moth; pest of various fruit and shade trees