New York river (6)
I believe the answer is:
hudson
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">new york river</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(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" .)