Radiata \Ra`di*a"ta\, n. pl. [NL., fr. radiatus, p. p. See Radiate.]

(Zo["o]l.) An extensive artificial group of invertebrates, having all the parts arranged radially around the vertical axis of the body, and the various organs repeated symmetrically in each ray or spheromere.

Note: It includes the c[oe]lenterates and the echinoderms. Formerly, the group was supposed to be a natural one, and was considered one of the grand divisions of the animal kingdom.

Source: Webster's Revised Unabridged Dictionary (1913)