New Orleans vs metropolis

New Orleans and metropolis both are nouns.

Word	Noun	Adjective	Verb	Adverb
New Orleans	Yes	No	No	No
metropolis	Yes	No	No	No

New Orleans (noun)	metropolis (noun)
a port and largest city in Louisiana; located in southeastern Louisiana near the mouth of the Mississippi river; a major center for offshore drilling for oil in the Gulf of Mexico; jazz originated here among black musicians in the late 19th century; Mardi Gras is celebrated here each year	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts