Throw light, maybe, on the outbuilding (4)
I believe the answer is:
shed
'the outbuilding' is the definition.
(shed is a kind of outbuilding)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for shed that I've seen before include "Get rid of - garden building" , "Garden feature" , "Get rid of -- moult" , "Get rid of - hut" , "Jettison" .)