Argun River vs river

Argun River and river both are nouns.

Word	Noun	Adjective	Verb	Adverb
Argun River	Yes	No	No	No
river	Yes	No	No	No

Argun River (noun)	river (noun)
a river in eastern Asia that arises in China and flows northeast along the border between China and Russia to become a tributary of the Amur River	a large natural stream of water (larger than a creek)