- (pl.) of Hydrozoon.
- (n.pl.) The Acalephae; one of the classes of coelenterates, including the Hydroidea, Discophora, and Siphonophora.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). hydrozoa. Retrieved September 21, 2026, from http://smartdefine.org/hydrozoa/definitions/2018167 |
| Chicago | Webster's. 2011. "hydrozoa" http://smartdefine.org/hydrozoa/definitions/2018167 (accessed September 21, 2026). |
| Harvard | Webster's 2011, hydrozoa, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/hydrozoa/definitions/2018167>. |
| MLA | Webster's. "hydrozoa" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/hydrozoa/definitions/2018167> |