river vs Volga

river and Volga both are nouns.

Word	Noun	Adjective	Verb	Adverb
river	Yes	No	No	No
Volga	Yes	No	No	No

river (noun)	Volga (noun)
a large natural stream of water (larger than a creek)	a Russian river; the longest river in Europe; flows into the Caspian Sea