Slough is quiet and expected to be evacuated (4)
I believe the answer is:
shed
'slough' is the definition.
(both can mean to remove or lose)
'quiet and expected to be evacuated' is the wordplay.
'quiet' becomes 'sh'.
'and' means one lot of letters go next to another.
'to be evacuated' says to hollow out the word (remove centre letters).
'expected' with its middle taken out is 'ed'.
'sh'+'ed'='SHED'
'is' acts as a link.
(Other definitions for shed that I've seen before include "Jettison" , "Discard; small building" , "Kind of hut - discard it" , "Drop; outhouse" , "Outhouse for storing garden tools etc" .)