St. Lawrence River vs river

St. Lawrence River and river both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. Lawrence River	Yes	No	No	No
river	Yes	No	No	No

St. Lawrence River (noun)	river (noun)
a North American river; flows into the Gulf of Saint Lawrence and the North Atlantic	a large natural stream of water (larger than a creek)