Disaster, calamity (11)
I believe the answer is:
catastrophe
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">disaster</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">calamity</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for catastrophe that I've seen before include "Event causing much damage" , "Sudden disaster" , "Terrible event" , "Event causing great damage" , "Event causing great suffering" .)