Trondheim vs urban center

Trondheim and urban center both are nouns.

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

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