River in remote estate (4)
I believe the answer is:
tees
'river' is the definition.
(River Tees )
'in remote estate' is the wordplay.
'in' says the answer is hidden in the clue.
'TEES' is hidden in the letters of 'remote estate'.
(Other definitions for tees that I've seen before include "Current" , "often damaged by drivers" , "banker" , "River of north-east England" , "Golf pegs" .)