Limber, supple (5)
I believe the answer is:
lithe
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">limber</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">supple</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that supple can be written as lithe)</span><br/ ><br/ ></span>
(Other definitions for lithe that I've seen before include "Supple and limber" , "showing great athletic ability" , "Lissome, supple" , "Of body, flexible and supple" , "Slim and supple" .)