sea anemone vs anthozoan

sea anemone and anthozoan both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea anemone	Yes	No	No	No
anthozoan	Yes	No	No	No

As nouns, anthozoan is a hypernym of sea anemone; that is, anthozoan is a word with a broader meaning than sea anemone:

sea anemone: marine polyps that resemble flowers but have oral rings of tentacles; differ from corals in forming no hard skeleton
anthozoan: sessile marine coelenterates including solitary and colonial polyps; the medusoid phase is entirely suppressed

Other hypernyms of sea anemone include actinozoan.

sea anemone (noun)	anthozoan (noun)
marine polyps that resemble flowers but have oral rings of tentacles; differ from corals in forming no hard skeleton	sessile marine coelenterates including solitary and colonial polyps; the medusoid phase is entirely suppressed