House in very bad area (5)
I believe the answer is:
villa
'house' is the definition.
(villa is a kind of house)
'very bad area' is the wordplay.
'very' becomes 'v' (abbreviation).
'bad' becomes 'i'll' (similar in meaning).
'area' becomes 'a' (maths abbreviation).
'v'+'ill'+'a'='VILLA'
'in' is the link.
(Other definitions for villa that I've seen before include "SECOND PART OF 8" , "Rented holiday home" , "Ancient Roman's country house" , "Ancient Roman country house" , "Detached house" .)