Defect, flaw (5)
I believe the answer is:
fault
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">defect</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">flaw</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for fault that I've seen before include "Defect; culpability" , "Blame" , "Defect or imperfection" , "Defect, mistake" , "Defect; blunder" .)