Hound knight kept in shed (4)
I believe the answer is:
hunt
'hound' is the definition.
('hunt' can be a synonym of 'hound')
'knight kept in shed' is the wordplay.
'knight' becomes 'n' (chess).
'kept in' means one lot of letters goes inside another.
'shed' becomes 'hut' (I've seen this before).
'n' placed within 'hut' is 'HUNT'.
(Other definitions for hunt that I've seen before include "Pursue game" , "Meeting with hounds" , "Meet - famous mountaineer" , "Forage" , "Search (with dogs?)" .)