metropolis vs Plano

metropolis and Plano both are nouns.

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

metropolis (noun)	Plano (noun)
people living in a large densely populated municipality	a city in northeastern Texas (suburb of Dallas) with counties Collin and Denton
a large and densely populated urban area; may include several independent administrative districts