Leningrad vs city

Leningrad and city both are nouns.

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

Leningrad (noun)	city (noun)
a city in the European part of Russia; 2nd largest Russian city; located at the head of the Gulf of Finland; former capital of Russia	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts
	an incorporated administrative district established by state charter