The term GROWN-UP SILKWORM is composed of two words: MOTH (4 letters) and SILKWORM. A MOTH is an insect that belongs to the order Lepidoptera, which includes butterflies and skippers. The SILKWORM is the larva or caterpillar of the domesticated silkmoth, Bombyx mori. It is a species of MOTH that is native to Asia and has been used for centuries to produce silk. Grown-up silkworms are adult moths that have emerged from their cocoons and are ready to mate and reproduce.