Elf, fairy (6)
I believe the answer is:
sprite
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">elf</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">fairy</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that fairy can be written as sprite)</span><br/ ><br/ ></span>
(Other definitions for sprite that I've seen before include "Puck, say" , "Impish type" , "Goblin, elf or imp" , "Pet, sir, could be a goblin" , "Nimble elf-like creature - icon in computer game" .)