Spear thrown in the direction of grass (7)
I believe the answer is:
esparto
'grass' is the definition.
(type of grass plant)
'spear thrown in the direction of' is the wordplay.
'thrown' indicates anagramming the letters.
'in the direction of' becomes 'to'.
'spear' anagrammed gives 'espar'.
'espar'+'to'='ESPARTO'
(Other definitions for esparto that I've seen before include "Grass, used for ropes, paper" , "Coarse type of grass" , "Rope-making process" , "Seaport (anag) - grass" , "Fibrous grass" .)