Aar vs Aare River

Aar and Aare River both are nouns.

Word	Noun	Adjective	Verb	Adverb
Aar	Yes	No	No	No
Aare River	Yes	No	No	No

As nouns, Aar and Aare River are synonyms defined as:

Aar and Aare River: a river in north central Switzerland that runs northeast into the Rhine

Other synonyms of Aar include Aare.

Aar (noun)	Aare River (noun)
a river in north central Switzerland that runs northeast into the Rhine	a river in north central Switzerland that runs northeast into the Rhine