Hero doing nothing to an audience (4)
I believe the answer is:
idol
'hero' is the definition.
(thesaurus)
'doing nothing to an audience' is the wordplay.
'doing nothing' becomes 'idle' (I've seen this before).
'to an audience' shows a homophone (sound like).
'idle' sounds like 'IDOL'.
(Other definitions for idol that I've seen before include "Darling" , "Figure of worship" , "Pop - - (TV)" , "'There's a one-eyed yellow -' (Hayes)" , "Object of worship (or love?)" .)