/ Dictionary / Index C cnidarian: Meaning and Definition of Find definitions for: cni•dar•i•an Pronunciation: (nī-dâr'ē-un), [key] — n. any invertebrate animal, as a hydra, jellyfish, sea anemone, or coral, considered as belonging to the phylum Cnidaria, characterized by the specialized stinging structures in the tentacles surrounding the mouth; a coelenterate. —adj. belonging or pertaining to the Cnidaria. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cnidarian (Thesaurus) Cnidaria cnido- Related Content Daily Word Quiz: quandary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language