A hostel in the heart of Colindale (3)
I believe the answer is:
inn
'a hostel' is the definition.
('inn' can be a synonym of 'hostel')
'in the heart of colindale' is the wordplay.
'the heart of' says to take the centre.
The centre of 'colindale' is 'n'.
'in'+'n'='INN'
(Other definitions for inn that I've seen before include "pubs?" , "Pub with lodging" , "Old hostelry for travellers" , "Hostel" , "Country pub, often with accommodation" .)