hydrozoan
Concise Oxford English Dictionary © 2008 Oxford University Press:
hydrozoan /ˌhʌɪdrə(ʊ)ˈzəʊən/ Zoology
▶noun a marine invertebrate (coelenterate) of the class Hydrozoa, which includes hydras and Portuguese men-of-war. ▶adjective relating to hydrozoans.
'hydrozoan' also found in these Oxford entries:

