(n) one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles, Syn. medusoid, medusan
a. [ Medusa + -oid. ] (Zool.) Like a medusa; having the fundamental structure of a medusa, but without a locomotive disk; -- said of the sessile gonophores of hydroids. -- n. A sessile gonophore. See Illust. under Gonosome. [ 1913 Webster ]