urban center vs Savannah

urban center and Savannah both are nouns.

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

urban center (noun)	Savannah (noun)
a large and densely populated urban area; may include several independent administrative districts	a port in eastern Georgia near the mouth of the Savannah river
	a river in South Carolina that flows southeast to the Atlantic