Destruction, slaughter (7)
I believe the answer is:
carnage
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">destruction</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">slaughter</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that slaughter can be written as carnage)</span><br/ ><br/ ></span>
(Other definitions for carnage that I've seen before include "Indiscriminate slaughter" , "'Massacre, slaughter (7)'" , "Mayhem" , "The killing of many people, slaughter" , "Bloodshed" .)