Brownsville vs urban center

Brownsville and urban center both are nouns.

Word	Noun	Adjective	Verb	Adverb
Brownsville	Yes	No	No	No
urban center	Yes	No	No	No

Brownsville (noun)	urban center (noun)
a city in southern Texas on the Rio Grande near its mouth into the Gulf of Mexico; has a channel that accommodates oceangoing ships	a large and densely populated urban area; may include several independent administrative districts