Nanking vs metropolis

Nanking and metropolis both are nouns.

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

Nanking (noun)	metropolis (noun)
a city in eastern China on the Yangtze River; a former capital of China; the scene of a Japanese massacre in the 1930s	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts