river vs Danau

river and Danau both are nouns.

Word	Noun	Adjective	Verb	Adverb
river	Yes	No	No	No
Danau	Yes	No	No	No

river (noun)	Danau (noun)
a large natural stream of water (larger than a creek)	the 2nd longest European river (after the Volga); flows from southwestern Germany to the Black Sea