Naples vs metropolis

Naples and metropolis both are nouns.

Word	Noun	Adjective	Verb	Adverb
Naples	Yes	No	No	No
metropolis	Yes	No	No	No

Naples (noun)	metropolis (noun)
a port and tourist center in southwestern Italy; capital of the Campania region	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts