Coelenterata
/sɪˌlɛntəˈreɪtə/Zoology
noun
1With plural (or occasionally singular) concord: a phylum or group of aquatic acoelomate invertebrates comprising the members of the present-day phyla Cnidaria and (in earlier use) Ctenophora. Also treated as plural: animals of this phylum (collectively or individually); coelenterates.
2Treated as plural. A major subdivision of the Metazoa, distinguished from the Coelomata by having an intestinal canal but no body cavity or coelom, and comprising the Porifera (sponges) as well as the Cnidaria and Ctenophora. Now historical.
Origin
Mid 19th century; earliest use found in Jabez Hogg (1817–1899), ophthalmic surgeon. From scientific Latin Coelenterata from ancient Greek κοῖλος hollow + ἔντερον + scientific Latin -ata.