Cedar Rapids vs metropolis

Cedar Rapids and metropolis both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cedar Rapids	Yes	No	No	No
metropolis	Yes	No	No	No

Cedar Rapids (noun)	metropolis (noun)
a city in eastern Iowa	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts