Zambezi River vs Zambezi

Zambezi River and Zambezi both are nouns.

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

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

Zambezi River and Zambezi: the fourth-longest river in Africa; flows into the Indian Ocean

Zambezi River (noun)	Zambezi (noun)
the fourth-longest river in Africa; flows into the Indian Ocean	the fourth-longest river in Africa; flows into the Indian Ocean