metropolis vs Porto

metropolis and Porto both are nouns.

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

metropolis (noun)	Porto (noun)
people living in a large densely populated municipality	port city in northwest Portugal; noted for port wine
a large and densely populated urban area; may include several independent administrative districts