Is obliged to be in South Ashford (3)
I believe the answer is:
has
'is obliged' is the definition.
'in south ashford' is the wordplay.
'in' indicates a hidden word.
'HAS' is hidden within 'south ashford'.
'to be' acts as a link.
(Other definitions for has that I've seen before include "Owns, holds" , "suffers from" , "Contains" , "Gives birth to" , "Cheats" .)