Western Siouan languages
The Western Siouan languages, also called Siouan proper or simply Siouan, are a large language family native to North America. They are closely related to the Catawban languages, sometimes called Eastern Siouan, and together with them constitute the Siouan (Siouan–Catawban) language family.
Sioux language
Closely related to the Sioux language are the Assiniboine and Stoney languages, whose speakers use the self-designation term (autonym) "Nakhóta" or "Nakhóda". Speakers of Lakota and Dakota have more difficulty understanding each of the two Nakoda languages (Assiniboine and Stoney).