Hydrozoa

Hy`dro`zo´a

n. pl.

1.

(Zool.) The Acalephæ; one of the classes of cœlenterates, including the Hydroidea, Discophora, and Siphonophora.

Thesaurus

Noun

1.

Hydrozoa - coelenterates typically having alternation of generations; hydroid phase is usually colonial giving rise to the medusoid phase by budding: hydras and jellyfishes class Hydrozoa Cnidaria, Coelenterata, phylum Cnidaria, phylum Coelenterata - hydras; polyps; jellyfishes; sea anemones; corals hydroid, hydrozoan - colonial coelenterates having the polyp phase dominant genus Hydra - hydras order Siphonophora, Siphonophora - marine colonial hydrozoans genus Sertularia, Sertularia - sessile hydroid that forms feathery colonies class - (biology) a taxonomic group containing one or more orders