Savannah vs urban center

Savannah and urban center both are nouns.

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

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