Neighbourhood police officer, authoritarian (8)
I believe the answer is:
district
'neighbourhood' is the definition.
(thesaurus)
'police officer authoritarian' is the wordplay.
'police officer' becomes 'di' (detective inspector).
'authoritarian' becomes 'strict' (I've seen this before).
'di'+'strict'='DISTRICT'
(Other definitions for district that I've seen before include "A quarter" , "'Area, territory (8)'" , "Precinct, section" , "Area of town or country" , "Area of a town or city" .)