1. the active immature form of an insect, especially one that differs greatly from the adult and forms the stage between egg and pupa, e.g. a caterpillar or grub.
▪ an immature form of other animals that undergo some metamorphosis, e.g. a tadpole.
Word Originmid 17th century (denoting a disembodied spirit or ghost): from Latin, literally ‘ghost, mask’.