any of various caterpillars (esp. genus Malacosoma, family Lasiocampidae) that usually live in colonies in large, tentlike webs spun among the branches of trees, which they defoliate
See tent caterpillar in American Heritage Dictionary 4
noun
Any of several destructive caterpillars of the family Lasiocampidae, especially of the genus Malacosoma, whose colonies construct silken tentlike webs in the branches of trees.