Willowy, slim (6)
I believe the answer is:
svelte
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">willowy</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">slim</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for svelte that I've seen before include "free" , "Slim and stylish" , "Elegant and of slender build" , "Slim and elegant" , "Lithe and lissom" .)