medusoid Syllabification: (me·du·soid)Pronunciation: /məˈdo͞oˌsoid, -ˌzoid/ ZoologyDefinition of medusoid adjective of, relating to, or resembling a medusa or jellyfish. of, relating to, or denoting the medusa phase in the life cycle of a coelenterate. Compare with polypoid (sense 1). noun a medusa or jellyfish. a medusoid reproductive bud. medusoid in other Oxford dictionaries Definition of medusoid in the British & World English dictionary