New Haven vs metropolis

New Haven and metropolis both are nouns.

Word	Noun	Adjective	Verb	Adverb
New Haven	Yes	No	No	No
metropolis	Yes	No	No	No

New Haven (noun)	metropolis (noun)
a city in southwestern Connecticut; site of Yale University	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts