On the mend leaving hospital somewhere in London (6)
I believe the answer is:
ealing
'somewhere in london' is the definition.
(I've seen this in other clues)
'on the mend leaving hospital' is the wordplay.
'on the mend' becomes 'healing' (on the mend means recovering from illness).
'leaving' indicates named letters should be taken away.
'hospital' becomes 'h' (abbreviation for hospital on maps).
'healing' with 'h' taken away is 'EALING'.
(Other definitions for ealing that I've seen before include "sort of comedy" , "part of London" , "West London district known for film studios" , "English film studio famous for comedies" , "Classic comedy 8 studio" .)