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Any of various invertebrate animals of the phylum Cnidaria, characterized by a radially symmetrical body with a saclike internal cavity and stinging nematocysts, and including the jellyfishes, hydras, sea anemones, and corals.
[New Latin Cnīdāria, phylum name, from Greek knīdē, sea nettle.]
(Animals) any invertebrate of the phylum Cnidaria, which comprises the coelenterates
(Animals) of, relating to, or belonging to the Cnidaria
[C20: from New Latin Cnidaria, from Greek knidē nettle]
cni•dar•i•an(naɪˈdɛər i ən)
1. any radially symmetric invertebrate of the phylum Cnidaria, including the hydras, jellyfishes, sea anemones, and corals, characterized by stinging cells and a saclike digestive cavity with a single opening surrounded by tentacles. Compare coelenterate.adj.
2. of or pertaining to the cnidarians.
Any of various invertebrate animals that have a body with radial symmetry, tentacles, and a sac-like internal cavity. They have a single opening for ingesting food and eliminating wastes. Cnidarians include the jellyfishes, hydras, sea anemones, and corals. Also called coelenterate.
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|Noun||1.||cnidarian - radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms|
coelenteron - the saclike body cavity of a coelenterate
invertebrate - any animal lacking a backbone or notochord; the term is not used as a scientific classification
Cnidaria, Coelenterata, phylum Cnidaria, phylum Coelenterata - hydras; polyps; jellyfishes; sea anemones; corals
polyp - one of two forms that coelenterates take (e.g. a hydra or coral): usually sedentary with a hollow cylindrical body usually with a ring of tentacles around the mouth; "in some species of coelenterate, polyps are a phase in the life cycle that alternates with a medusoid phase"
medusan, medusoid, medusa - one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles
jellyfish - any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans
scyphozoan - any of various usually free-swimming marine coelenterates having a gelatinous medusoid stage as the dominant phase of its life cycle