Piece of foliage (4)
I believe the answer is:
leaf
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">piece of foliage</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 leaf that I've seen before include "Page of a book" , "Small part of wood" , "Bit of foliage" , "Part of a plant and of a book" , "Turn over a new one to reform" .)