1. The larva or a worm with a long soft body, many short legs, and that often has brightly colored or spiny skin: The caterpillar develops and changes into a butterfly or a moth.
2. Etymology: from Latin catta pilosa, "hairy cat".

Literally, "a hairy she-cat", the word being derived from Old (North) French catte (French chatte, "she-cat") and pelue, "hairy".