Unemployed star on radio (4)
I believe the answer is:
idle
'unemployed' is the definition.
('idle' is associated in meaning with 'unemployed')
'star on radio' is the wordplay.
'star' becomes 'idol' (idol is a kind of star).
'on radio' shows a homophone (sound like).
'idol' is a homophone of 'IDLE'.
(Other definitions for idle that I've seen before include "Unoccupied (time); run (engine) slowly" , "Indolent" , "without basis" , "Inactive - lied (anag)" , "Not busy" .)