(in some classification systems) a major grouping that includes more or less radially symmetrical animals, as coelenterates (jellyfish, sea anemones, corals), ctenophores (comb jellies), and echinoderms (starfish, sea urchins, sea cucumbers).
Origin: 1820–30; < NL, n. use of neut. pl. of L radiātusradiate(adj.)