river vs Amur River

river and Amur River both are nouns.

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

river (noun)	Amur River (noun)
a large natural stream of water (larger than a creek)	an Asian river between China and Russia; flows into the Sea of Okhotsk