Voting district (4)
I believe the answer is:
ward
'voting district' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ward that I've seen before include "number of patients" , "Doctor in 5A 1D [PROFUMO AFFAIR]" , "Separate room" , "Division of borough" , "Councillor's area" .)