Broadcast national fixture (3)
I believe the answer is:
tie
'fixture' is the definition.
(I've seen this before)
'broadcast national' is the wordplay.
'broadcast' shows a homophone (sound like) (how the word might sound on the radio or TV).
'national' becomes 'thai' ('Thai' is an example).
'thai' is a homophone of 'TIE'.
(Other definitions for tie that I've seen before include "Drawn score" , "No-win situation" , "Draw for neckware" , "Neckpiece" , "Finish level" .)