River Trent vs river

River Trent and river both are nouns.

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

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