metropolis vs Atlantic City

metropolis and Atlantic City both are nouns.

Word	Noun	Adjective	Verb	Adverb
metropolis	Yes	No	No	No
Atlantic City	Yes	No	No	No

metropolis (noun)	Atlantic City (noun)
people living in a large densely populated municipality	a city on the Atlantic shore in southeastern New Jersey; a resort and gambling center
a large and densely populated urban area; may include several independent administrative districts