A silkworm is the young form of a Chinese moth and it produces silk.
silkworm in British English
(ˈsɪlkˌwɜːm)
noun
1.
the larva of the Chinese moth Bombyx mori, that feeds on the leaves of the mulberry tree: widely cultivated as a source of silk
2.
any of various similar or related larvae
3. silkworm moth
silkworm in American English
(ˈsɪlkˌwɜrm)
noun
any of certain moth caterpillars (esp. family Bombycidae) that produce cocoons of silk fiber: they feed chiefly on mulberry leaves, and some species (esp. Bombyx mori) are cultivated as the source of commercial silk