Death in short, a terrible sin (8)
I believe the answer is:
curtains
'death' is the definition.
(I've seen this before)
'short a terrible sin' is the wordplay.
'short' becomes 'curt' ('curt' can be a synonym of 'short'**).
'terrible' is an anagram indicator.
'sin' with letters rearranged gives 'ins'.
'curt'+'a'+'ins'='CURTAINS'
'in' is the link.
(Other definitions for curtains that I've seen before include "Window drapes in slangy ending" , "theatre equipment!" , "Death (slang)" , "Hanging cloths" , "Draperies" .)