Feeling of boredom (5)
I believe the answer is:
ennui
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">feeling of boredom</span>' is the definition.<br/ ><span class="explanation-format__explanation">(ennui is a feeling of boredom or discontent)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ennui that I've seen before include "French boredom and lassitude" , "Weary feeling" , "Lack of interest" , "Bored listlessness" , "Effect of boredom" .)