Murrumbidgee River vs river

Murrumbidgee River and river both are nouns.

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

Murrumbidgee River (noun)	river (noun)
a river of southeastern Australia; flows westward into the Murray River	a large natural stream of water (larger than a creek)