scyphistoma

noun

scy·​phis·​to·​ma sī-ˈfi-stə-mə 

plural scyphistomae sī-ˈfi-stə-(ˌ)mē  also scyphistomas

: a sexually produced scyphozoan larva that ultimately repeatedly constricts transversely to form free-swimming medusae

Word History

Etymology

New Latin, from Latin scyphus cup + Greek stoma mouth — more at stomach entry 1

First Known Use

1861, in the meaning defined above