Wind up industry leader on the radio (7)
I believe the answer is:
tighten
'wind up' is the definition.
(I've seen this in another clue)
'industry leader on the radio' is the wordplay.
'industry leader' becomes 'titan' (I've seen this in another clue).
'on the radio' shows a homophone (sound like).
'titan' is a homophone of 'TIGHTEN'.
(Other definitions for tighten that I've seen before include "Make less loose" , "Make more secure or tense" , "Make more strict" , "put the squeeze on" , "get tense" .)