metropolis vs Kaunas

metropolis and Kaunas both are nouns.

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

metropolis (noun)	Kaunas (noun)
people living in a large densely populated municipality	a city in central Lithuania
a large and densely populated urban area; may include several independent administrative districts