Dictionary entry

Cnidaria

Webster's Dictionary 1913

‖Cni‐da″ri‐a (nĭ‐dā″rĭ‐ȧ), n. pl. [NL. See Cnida.] (Zoöl.) A comprehensive group equivalent to the true Cœlenterata, i.e., exclusive of the sponges. They are so named from presence of stinging cells (cnidae) in the tissues. See Coelenterata.