Cankerworm

Part of speech: noun

Definitions

1. A larval stage of certain moths that resembles a worm and is known for damaging leaves, which can ultimately hurt plant health and biodiversity
2. A caterpillar form of specific moths notorious for its leaf-eating behavior that causes significant harm to trees and shrubs and can disrupt local ecosystems
3. A specific type of caterpillar belonging to certain moth species that feeds on leaves, often leading to severe damage to foliage and potentially impacting entire plant communities

Etymology: Cankerworm is one of those compounds where the parts tell the whole story. "Canker" once meant a sore or ulcer, and in its older sense it was used for the gnawing, eating kind of damage, so a "canker" was something that ate away at what it touched. "Worm" in Old English was a broader word than it is now, covering any small creeping or crawling creature, including caterpillars. Put together, the name describes a worm that eats its way through leaves, the way a canker eats into flesh. The word is a plain English compound, formed from "canker" and "worm" and built in the same way as many other older names for crawling pests. It is applied to the larvae of certain moths, such as the spring and fall cankerworms, whose feeding can strip large numbers of trees bare in a single season.