Unemployed star in audition (4)
I believe the answer is:
idle
'unemployed' is the definition.
(similar in meaning)
'star in audition' is the wordplay.
'star' becomes 'idol' (idol is a kind of star).
'in audition' shows a homophone (sound like) (audition can mean hearing).
'idol' is a homophone of 'IDLE'.
(Other definitions for idle that I've seen before include "Monty Python's Eric, b. 1943" , "loiter aimlessly" , "Indolent" , "'Lazy, not doing anything (4)'" , "Explosive stuff" .)