metropolis vs Kovno

metropolis and Kovno both are nouns.

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

metropolis (noun)	Kovno (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