Xian vs urban center

Xian and urban center both are nouns.

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

Xian (noun)	urban center (noun)
a city of central China; capital of ancient Chinese empire 221-206 BC	a large and densely populated urban area; may include several independent administrative districts