1. The newly hatched, wingless, often wormlike form of many insects before metamorphosis.
2. The newly hatched, earliest stage of any of various animals that undergo metamorphosis, differing markedly in form and appearance from the adult.
3. Roman Mythology A malevolent spirit of the dead; a lemur.

Word History: The word larva referring to the newly hatched form of insects before they undergo metamorphosis comes from the Latin word lārva, meaning "evil spirit, demon, devil." To understand why this should be so, first we need to know that the Latin word also was used for a terrifying mask, and in Medieval Latin it could mean "mask or visor." Larva is therefore an appropriate term for that stage of an insect's life during which its final form is still hidden or masked, and New Latin lārva was thus applied in 1691 by Carolus Linnaeus, the Swedish botanist who originated our system of classifying plants and animals. The word larva is first recorded in English in its scientific sense in 1768, although it had been used in its "spirit" sense in 1651 in a way that foreshadowed the usage by Linnaeus.