Possibly Roman police district? (5)
I believe the answer is:
manor
'police district?' is the definition.
(I've seen this before)
'possibly roman' is the wordplay.
'possibly' indicates anagramming the letters.
'roman' with letters rearranged gives 'MANOR'.
(Other definitions for manor that I've seen before include "Large country house with lands" , "Grand but strange Roman house" , "lord's home" , "house on estate" , "home territory" .)