Tuft of grass (7)
I believe the answer is:
tussock
'tuft of grass' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tussock that I've seen before include "Dense clump of grass - stuck so (anag)" , "hump" , "Bushy clump of grass" , "mound" , "(Of grass) cut" .)