Cologne vs metropolis

Cologne and metropolis both are nouns.

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

Cologne (noun)	metropolis (noun)
a commercial center and river port in western Germany on the Rhine River; flourished during the 15th century as a member of the Hanseatic League	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts