n.
Pronunciation: ˌ h ī -dr ə - ' z ō - ə n
Function: noun
Etymology: ultimately from Greek hydr- + z ō ion animal ― more at ZO-
Date: 1877
: any of a class (Hydrozoa) of coelenterates that includes solitary and colonial polyps and jellyfishes having no stomodeum or gastric tentacles
– hydrozoan adjective