metropolis vs Duluth

metropolis and Duluth both are nouns.

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

metropolis (noun)	Duluth (noun)
people living in a large densely populated municipality	a city in northeast Minnesota on Lake Superior
a large and densely populated urban area; may include several independent administrative districts