A Great Lake (4)
'a great lake' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ontario that I've seen before include "provincial area" , "part of Canada" , "part of N America" , "vast lake" , "Oration in Canadian province" .)
'a great lake' is the definition.
(Erie is one of the Great Lakes)
This is all the clue.
(Other definitions for erie that I've seen before include "North american lake sounds spooky" , "N. American lake" , "Superior companion" , "Buffalo's lake" , "The lake sounds weird" .)