Osier (6)
I believe the answer is:
willow
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">osier</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for willow that I've seen before include "One [TYPE OF TREE]" , "See 22" , "Quick-growing tree with flexible branches" , "Cricket bat wood" , "Tree of the salix family" .)