Huambo vs urban center

Huambo and urban center both are nouns.

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

Huambo (noun)	urban center (noun)
a city in the mountains in western Angola	a large and densely populated urban area; may include several independent administrative districts