Lake at one end of the Niagara River (4)
I believe the answer is:
erie
'lake at one end of the niagara river' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for erie that I've seen before include "Superior companion" , "Great lake in Eire" , "North american lake sounds spooky" , "The lake sounds weird" , "Lake between Canada and the US" .)