Chaos, pandemonium (5)
I believe the answer is:
havoc
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">chaos</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">pandemonium</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for havoc that I've seen before include "Chaos and destruction" , "Great confusion" , "Carnage" , "Disaster" , "Chaos, confusion" .)