Deliberately destroy (8)
I believe the answer is:
sabotage
'deliberately destroy' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sabotage that I've seen before include "Subversion by inflicting damage" , "Treachery!" , "Scupper" , "Deliberately destroy" , "Deliberate damage (eg, in wartime)" .)