hydrozoan

American  

[hahy-druh-zoh-uhn] / ˌhaɪ drəˈzoʊ ən /

noun

1. any freshwater or marine coelenterate of the class Hydrozoa, including free-swimming or attached types, as the hydra, in which one developmental stage, either the polyp or medusa, is absent, and colonial types, as the Portuguese man-of-war, in which both medusa and polyp stages are present in a single colony.

---

adjective

1. belonging or pertaining to the Hydrozoa.

hydrozoan British  

/ ˌhaɪdrəʊˈzəʊən /

noun

1. any colonial or solitary coelenterate of the class Hydrozoa, which includes the hydra, Portuguese man-of-war, and the sertularians

---

adjective

1. of, relating to, or belonging to the Hydrozoa

Etymology

Origin of hydrozoan

1875–80; < New Latin Hydrozo ( a ) ( see hydro- ¹, -zoa) + -an

Example Sentences

These sea snails are also voracious predators themselves and feast upon free-floating hydrozoan such as Velella velella and Portuguese man o’ war.

From Los Angeles Times • Jul. 23, 2025

They claim to have found compelling genetic evidence that at least a few members of each colony of the little marine hydrozoan were unrelated to the organism that founded it, making them chimeras.

From Scientific American • Sep. 15, 2018

"Nonclonal coloniality: Genetically chimeric colonies through fusion of sexually produced polyps in the hydrozoan Ectopleura larynx."

From Scientific American • Sep. 15, 2018

Gonophore, gon′o-fōr, n. the ultimate generative zooid of a hydrozoan, originating directly the generative elements.

From Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) by Various

Interrā′dius, an interradial part, esp. of a hydrozoan.

From Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) by Various