river vs Severn River

river and Severn River both are nouns.

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

river (noun)	Severn River (noun)
a large natural stream of water (larger than a creek)	a river in England and Wales flowing into the Bristol Channel; the longest river in Great Britain
	a river in Ontario that flows northeast into Hudson Bay