Small flying insect (4)
I believe the answer is:
gnat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">small flying insect</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for gnat that I've seen before include "Stinging insect" , "little irritation" , "Small fly that bites" , "Tang of a biting fly" , "Small bloodsucker" .)