New York river (6)
I believe the answer is:
hudson
'new york river' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for hudson that I've seen before include "River in New York city" , "Rock --, US actor" , "Major inland sea of NE Canada - . . . . . . Bay" , "navigator" , "8 [BUTLER" .)