Made money on the radio (4)
I believe the answer is:
bred
'made' is the definition.
(breeding is a kind of making)
'money on the radio' is the wordplay.
'money' becomes 'bread' (bread is slang for money).
'on the radio' shows a homophone (sound like).
'bread' is a homophone of 'BRED'.
(Other definitions for bred that I've seen before include "Developed (animal variety)" , "Produced offspring" , "Multiplied" , "Procreated" , "Very (music)" .)