metropolis vs Solingen

metropolis and Solingen both are nouns.

Word	Noun	Adjective	Verb	Adverb
metropolis	Yes	No	No	No
Solingen	Yes	No	No	No

metropolis (noun)	Solingen (noun)
people living in a large densely populated municipality	a city in west central Germany noted for cutlery
a large and densely populated urban area; may include several independent administrative districts