Salonica vs urban center

Salonica and urban center both are nouns.

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

Salonica (noun)	urban center (noun)
a port city in northeastern Greece on an inlet of the Aegean Sea; second largest city of Greece	a large and densely populated urban area; may include several independent administrative districts