Murray River vs Commonwealth of Australia

Murray River and Commonwealth of Australia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Murray River	Yes	No	No	No
Commonwealth of Australia	Yes	No	No	No

Murray River (noun)	Commonwealth of Australia (noun)
a southeast Australian river; flows westward and then south into the Indian Ocean at Adelaide	a nation occupying the whole of the Australian continent; Aboriginal tribes are thought to have migrated from southeastern Asia 20,000 years ago; first Europeans were British convicts sent there as a penal colony