urban center vs Halicarnassus

urban center and Halicarnassus both are nouns.

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

urban center (noun)	Halicarnassus (noun)
a large and densely populated urban area; may include several independent administrative districts	an ancient Greek city on the southwestern coast of Asia Minor in what is now Turkey; site of the mausoleum at Halicarnassus