city vs Omaha

city and Omaha both are nouns.

Word	Noun	Adjective	Verb	Adverb
city	Yes	No	No	No
Omaha	Yes	No	No	No

city (noun)	Omaha (noun)
people living in a large densely populated municipality	thoroughbred that won the triple crown in 1935
a large and densely populated urban area; may include several independent administrative districts	the Dhegiha dialect spoken by the Omaha
an incorporated administrative district established by state charter	largest city in Nebraska; located in eastern Nebraska on the Missouri river; a major transportation center of the Midwest
	a member of the Siouan people formerly living in the Missouri river valley in northeastern Nebraska