Cast off hut (4)
I believe the answer is:
shed
I believe this clue is a double definition.
'cast off' is the first definition.
(synonyms)
'hut' is the second definition.
(hut in a garden)
(Other definitions for shed that I've seen before include "storage unit" , "Remove clothes in small hut" , "Discard; small building" , "In which tools may be" , "Simple building; discard" .)