Definition of "cnidarian" []

• Any of various invertebrate animals of the phylum Cnidaria, characterized by a radially symmetrical body with a saclike internal cavity, and including the jellyfishes, hydras, sea anemones, and corals. Also called coelenterate. (noun)
• Of, relating to, or belonging to the phylum Cnidaria. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "A first striking finding was the high number of SOX gene sequences recovered from both the cnidarian and the ctenophore representatives (10 and 13 from C. hemisphaerica and P. pileus, respectively)."
• "The ancestral cnidarian proto-Hox cluster is thought to have contained four Hox genes."
• "Based on the clear clustering of the Wnt gene families it is highly unlikely that a single Wnt gene independently expanded in the cnidarian and vertebrate lineages."