Irtish River vs Irtish

Irtish River and Irtish both are nouns.

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

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

Irtish River and Irtish: an Asian river that rises in the Altai Mountains in northern China and flows generally northwest to become a tributary of the Ob River

Other synonyms of Irtish River include Irtysh, Irtysh River.

Irtish River (noun)	Irtish (noun)
an Asian river that rises in the Altai Mountains in northern China and flows generally northwest to become a tributary of the Ob River	an Asian river that rises in the Altai Mountains in northern China and flows generally northwest to become a tributary of the Ob River