A fight in the neighbourhood (5)
I believe the answer is:
about
'the neighbourhood' is the definition.
(thesaurus)
'a fight' is the wordplay.
'fight' becomes 'bout' ('bout' can be a synonym of 'fight').
'a'+'bout'='ABOUT'
'in' acts as a link.
(Other definitions for about that I've seen before include "On the topic of" , "Moving" , "Concerning or in neighbourhood" , "Close to" , "Concerning; approximately" .)