Caterpillar is probably from Old North French catepelose ('hairy cat'), from cate ('cat') + pelose ('hairy', from Latin pilosus), the form later influenced by piller ('plunderer') because caterpillars strip plants. The historical trail runs through catepelose in Old French and pilosus in Latin. Morphologically, caterpillar is transparent: probably from Old North French catepelose ('hairy cat'), from cate ('cat') + pelose ('hairy', from Latin pilosus), the form later influenced by piller ('plunderer') because caterpillars strip plants. Used as a noun, caterpillar now means "the larva of a butterfly or moth", so the present definition can be read against the older forms and meanings. The result is a borrowed or transmitted form whose modern spelling carries a compact record of its route into English.