metropolis vs Izmir

metropolis and Izmir both are nouns.

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

metropolis (noun)	Izmir (noun)
people living in a large densely populated municipality	a port city in western Turkey
a large and densely populated urban area; may include several independent administrative districts