Dnieper vs Dnieper River

Dnieper and Dnieper River both are nouns.

Word	Noun	Adjective	Verb	Adverb
Dnieper	Yes	No	No	No
Dnieper River	Yes	No	No	No

As nouns, Dnieper and Dnieper River are synonyms defined as:

Dnieper and Dnieper River: a river that rises in Russia near Smolensk and flowing south through Belarus and Ukraine to empty into the Black Sea

Dnieper (noun)	Dnieper River (noun)
a river that rises in Russia near Smolensk and flowing south through Belarus and Ukraine to empty into the Black Sea	a river that rises in Russia near Smolensk and flowing south through Belarus and Ukraine to empty into the Black Sea