urban center vs Leyden

urban center and Leyden both are nouns.

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

urban center (noun)	Leyden (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in the western Netherlands; residence of the Pilgrim Fathers for 11 years before they sailed for America in 1620