I'll get him bad publicity (9)
I believe the answer is:
limelight
'publicity' is the definition.
(thesaurus)
'i'll get him bad' is the wordplay.
'bad' is an anagram indicator.
'ill'+'get'+'him'='illgethim'
'illgethim' with letters rearranged gives 'LIMELIGHT'.
(Other definitions for limelight that I've seen before include "centre of public attention" , "Chaplin 1952 film" , "The glare of publicity" , "Intense publicity like stage illumination" , "Media attention" .)