Fixes London area with remedies (7)
I believe the answer is:
secures
'fixes' is the definition.
('secure' can be a synonym of 'fix')
'london area with remedies' is the wordplay.
'london area' becomes 'SE' (abbreviation for South East).
'with' means one lot of letters go next to another.
'remedies' becomes 'cures' ('cure' can be a synonym of 'remedy').
'se'+'cures'='SECURES'
(Other definitions for secures that I've seen before include "Guarantees" , "Ties down" , "Makes firmly attached" , "Closes, fortifies" , "Makes safe through rescues" .)