Church lease runs out in London (7)
I believe the answer is:
chelsea
'in london' is the definition.
(I've seen this before)
'church lease runs out' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'runs' indicates an anagram.
'out' is an insertion indicator.
'lease' is an anagram of 'elsea'.
'ch' inserted into 'elsea' is 'CHELSEA'.
(Other definitions for chelsea that I've seen before include "District of London (with famous pensioners)" , "Type of sugared currant bun" , "London borough with annual Flower Show" , "upmarket part of London" , "Part of our capital" .)