river vs Indus River

river and Indus River both are nouns.

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

river (noun)	Indus River (noun)
a large natural stream of water (larger than a creek)	an Asian river that rises in Tibet and flows through northern India and then southwest through Kashmir and Pakistan to the Arabian Sea