metropolis vs Pisa

metropolis and Pisa both are nouns.

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

metropolis (noun)	Pisa (noun)
people living in a large densely populated municipality	a city in Tuscany; site of the famous Leaning Tower
a large and densely populated urban area; may include several independent administrative districts