metropolis vs Curitiba

metropolis and Curitiba both are nouns.

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

metropolis (noun)	Curitiba (noun)
people living in a large densely populated municipality	a city in southeastern Brazil
a large and densely populated urban area; may include several independent administrative districts