Piece of grass (5)
I believe the answer is:
blade
'piece of grass' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for blade that I've seen before include "A knife, or a dashing fellow" , "London rail terminus" , "Runner on an ice-skate" , "Leaf, of grass, say" , "Flat part of an oar" .)