Sprite, gremlin (3)
I believe the answer is:
imp
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">sprite</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that imp is a type of sprite)</span><br/ ><br/ >'<span class="explanation-format__original">gremlin</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(both can mean a mischievous creature)</span><br/ ><br/ ></span>
(Other definitions for imp that I've seen before include "Scallywag" , "Sprite; add feathers to" , "A mischievous little devil" , "Young troublemaker" , "one likely to cause trouble" .)