Broadcast medium (5)
I believe the answer is:
radio
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">broadcast medium</span>' is the definition.<br/ ><span class="explanation-format__explanation">(radio is a broadcast medium)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for radio that I've seen before include "Electronic receiver" , "listening device" , "Communicate with" , "Broadcaster" , "Transmit" .)