Definition of palmerworm

• n. - Any hairy caterpillar which appears in great numbers, devouring herbage, and wandering about like a palmer. The name is applied also to other voracious insects.
• n. - In America, the larva of any one of several moths, which destroys the foliage of fruit and forest trees, esp. the larva of Ypsolophus pometellus, which sometimes appears in vast numbers.