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