Thunder Bay vs metropolis

Thunder Bay and metropolis both are nouns.

Word	Noun	Adjective	Verb	Adverb
Thunder Bay	Yes	No	No	No
metropolis	Yes	No	No	No

Thunder Bay (noun)	metropolis (noun)
a port city in Ontario on Lake Superior	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts