Clobber good listener (4)
I believe the answer is:
gear
'clobber' is the definition.
(thesaurus)
'good listener' is the wordplay.
'good' becomes 'g' (abbreviation).
'listener' becomes 'ear' (I've seen this before**).
'g'+'ear'='GEAR'
(Other definitions for gear that I've seen before include "Toothed wheel and youthful fashion" , "Toothed wheel which engages with another one" , "Clothes - equipment - first to fifth in a car?" , "Effects" , "Toothed wheel, equipment and clothes" .)