Other barn destroyed: it's detestable (9)
I believe the answer is:
abhorrent
'detestable' is the definition.
(synonyms)
'other barn destroyed' is the wordplay.
'destroyed' indicates an anagram.
'other'+'barn'='otherbarn'
'otherbarn' anagrammed gives 'ABHORRENT'.
'it's' acts as a link.
(Other definitions for abhorrent that I've seen before include "noisome" , "Horrible" , "Detestable, really off-putting" , "hateful" , "Earthborn (anag) - detestable" .)