Araguaia River vs Araguaya

Araguaia River and Araguaya both are nouns.

Word	Noun	Adjective	Verb	Adverb
Araguaia River	Yes	No	No	No
Araguaya	Yes	No	No	No

As nouns, Araguaia River and Araguaya are synonyms defined as:

Araguaia River and Araguaya: a river in central Brazil that flows generally northward (with many falls) to join the Tocantins River

Other synonyms of Araguaia River include Araguaia, Araguaya River.

Araguaia River (noun)	Araguaya (noun)
a river in central Brazil that flows generally northward (with many falls) to join the Tocantins River	a river in central Brazil that flows generally northward (with many falls) to join the Tocantins River