Matamoros vs metropolis

Matamoros and metropolis both are nouns.

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

Matamoros (noun)	metropolis (noun)
a city in northeastern Mexico opposite Brownsville near the mouth of the Rio Grande	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts