river vs Trent River

river and Trent River both are nouns.

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

river (noun)	Trent River (noun)
a large natural stream of water (larger than a creek)	a river in central England that flows generally northeastward to join with the Ouse River and form the Humber