a metallic runner with a frame shaped to fit the sole of a shoe, -- made to be fastened under the foot, and used for moving rapidly on ice.-to move on skates.-any one of numerous species of large, flat elasmobranch fishes of the genus raia, having a long, slender tail, terminated by a small caudal fin. the pectoral fins, which are large and broad and united to the sides of the body and head, give a somewhat rhombic form to these fishes. the skin is more or less spinose.