urban center vs Grozny

urban center and Grozny both are nouns.

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

urban center (noun)	Grozny (noun)
a large and densely populated urban area; may include several independent administrative districts	the capital of Chechnya in southwestern Russia; center of extensive oil fields