river vs Arauca River

river and Arauca River both are nouns.

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

river (noun)	Arauca River (noun)
a large natural stream of water (larger than a creek)	a river that rises in northern Colombia and flows generally eastward to the Orinoco in central Venezuela