1. (Science: physics) The transmission and reception of electric impulses or signals by means of electric waves without a connecting wire, or the use of these waves for the wireless transmission of electric impulses into which sound is converted.
2. (Science: anatomy, prefix) A combining form indicating connection with, or relation to, a radius or ray; specifically, with the radius of the forearm; as, radio-ulnar, radiomuscular, radiocarpal.
Origin: L. Radius, ray