Knoxville vs metropolis

Knoxville and metropolis both are nouns.

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

Knoxville (noun)	metropolis (noun)
a city in eastern Tennessee on the Tennessee River	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts