- any invertebrate animal of the phylum Coelenterata, including the hydras, jellyfishes, sea anemones, and corals, characterized by a single internal cavity serving for digestion, excretion, and other functions and having tentacles on the oral end.
- belonging or pertaining to the Coelenterata.
- any invertebrate of the phylum Cnidaria (formerly Coelenterata), having a saclike body with a single opening (mouth), which occurs in polyp and medusa forms. Coelenterates include the hydra, jellyfishes, sea anemones, and corals
- (loosely) any invertebrate of the phyla Cnidaria or Ctenophora
- of or relating to coelenterates
