Qualm; uncertainty (5)
I believe the answer is:
doubt
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">qualm</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">uncertainty</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that uncertainty can be written as doubt)</span><br/ ><br/ ></span>
(Other definitions for doubt that I've seen before include "Suspicion" , "Uncertainty about the truth" , "Suspect" , "Distrust" , "Misgiving" .)