river vs Vetluga

river and Vetluga both are nouns.

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

river (noun)	Vetluga (noun)
a large natural stream of water (larger than a creek)	a river in central Russia; flows generally southward into the Volga