St. Petersburg vs Russia

St. Petersburg and Russia both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. Petersburg	Yes	No	No	No
Russia	Yes	No	No	No

St. Petersburg (noun)	Russia (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	a former communist country in eastern Europe and northern Asia; established in 1922; included Russia and 14 other soviet socialist republics (Ukraine and Byelorussia and others); officially dissolved 31 December 1991
a city in western Florida on Tampa Bay; a popular winter resort	formerly the largest Soviet Socialist Republic in the USSR occupying eastern Europe and northern Asia
	a former empire in eastern Europe and northern Asia created in the 14th century with Moscow as the capital; powerful in the 17th and 18th centuries under Peter the Great and Catherine the Great when Saint Petersburg was the capital; overthrown by revolution in 1917
	a federation in northeastern Europe and northern Asia; formerly Soviet Russia; since 1991 an independent state