Boredom, dissatisfaction (5)
I believe the answer is:
ennui
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">boredom</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">dissatisfaction</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(ennui is a kind of dissatisfaction)</span><br/ ><br/ ></span>
(Other definitions for ennui that I've seen before include "Boredom, tedium" , "Weary feeling" , "Feeling of weariness or boredom" , "to make one list less when connected" , "Boredom, listlessness" .)