Deliberately destroy (8)
I believe the answer is:
sabotage
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">deliberately destroy</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sabotage that I've seen before include "Subversion by inflicting damage" , "Treachery!" , "Scupper" , "Deliberately destroy" , "Deliberate damage (eg, in wartime)" .)