Definition of radial canal
1
: one of the numerous minute canals lined with choanocytes which radiate from the paragastric cavity in some sponges and end just below the surface of the sponge
2
: one of the canals extending through the substance of the umbrella from the gastric cavity to the marginal circular canal in jellyfishes
3
: a tube extending outward along each ambulacral area from the circumoral canal in most echinoderms
