urban center vs Sevastopol

urban center and Sevastopol both are nouns.

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

urban center (noun)	Sevastopol (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in southern Ukraine on the Black Sea