urban center vs Nidaros

urban center and Nidaros both are nouns.

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

urban center (noun)	Nidaros (noun)
a large and densely populated urban area; may include several independent administrative districts	a port in central Norway on Trondheim Fjord