I think we're getting pretty close to "No True Scotsman" territory when we start designating neighborhoods --- inside the city limits of a metro statistical area with vast, sprawling suburbs --- as themselves suburbs, despite being on trunk CTA train routes, on one of the city's main drags, because "European cities would call those neighborhoods suburbs".

I'm getting the impression that Europeans would "call them suburbs" because they have affordable single-family houses in them, which makes this debate pretty disingenuous.