radial symmetry definition
radial symmetry. n. 1. (Biology) a type of structure of an organism or part of an organism in which a vertical cut through the axis in any of two or more planes produces two halves that are mirror images of each other. Compare bilateral symmetry.oun. 1. radial symmetry-the property of symmetry about an axis; the starfish illustrates radial symmetry. symmetricalness, symmetry, correspondence, balance - (mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane.