river vs Oder River

river and Oder River both are nouns.

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

river (noun)	Oder River (noun)
a large natural stream of water (larger than a creek)	a European river which rises in the Czech republic and flows through western Poland; flows into the Baltic Sea