metropolis vs Douala

metropolis and Douala both are nouns.

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

metropolis (noun)	Douala (noun)
people living in a large densely populated municipality	the largest city of Cameroon
a large and densely populated urban area; may include several independent administrative districts