City in northwestern Pennsylvania (4)
I believe the answer is:
erie
'city in northwestern pennsylvania' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for erie that I've seen before include "Great lake in Eire" , "One of the Great Lakes" , "Buffalo's lake" , "The lake sounds weird" , "North american lake sounds spooky" .)