River passing through West Ham estate (6)
I believe the answer is:
thames
'river' is the definition.
(English river)
'passing through west ham estate' is the wordplay.
'passing through' indicates a hidden word.
'THAMES' is hidden within 'west ham estate'.
(Other definitions for thames that I've seen before include "River at Runnymede" , "Longest English river" , "capital banker" , "River at Windsor" , "London flood control" .)