Radio- /(rā"dĭ*ō̇-)/

Ra·di·o-

Radio-

a.
  1. Of or pertaining to, or employing, or operated by, radiant energy, specifically that of electromagnetic waves with frequencies between those of infrared radiation and X-rays; hence, pertaining to, or employed in, broadcast radio or television, microwaves, radiotelephones, etc.; as, radio waves.
  2. of or pertaining to broadcast radio; as, a radio program.

Radio-
  1. A combining form indicating connection with, or relation to, a radius or ray; specifically (Anat.), with the radius of the forearm; as, radio-ulnar, radio-muscular, radio-carpal. (Anat.)