Piece of foliage (4)
I believe the answer is:
leaf
'piece of foliage' is the definition.
(I've seen this before)
This is the entire clue.
(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" .)