Informer in pasture (5)
I believe the answer is:
grass
I believe this is a double definition.
'informer' is the first definition.
(I've seen this before)
'pasture' is the second definition.
(I've seen this before)
'in' acts as a link.
(Other definitions for grass that I've seen before include "shop" , "Cannabis (colloq.), informer (colloq.)" , "Plant used for lawns" , "Perhaps bent" , "copper may rely on him?" .)