Siouan languages
Siouan or Siouan–Catawban is a language family of North America that is located primarily in the Great Plains, Ohio and Mississippi valleys and southeastern North America with a few other languages in the east.
Lakota people
The Lakota (pronounced , Lakota language: Lakȟóta) are a Native American tribe. Also known as the Teton Sioux (from "Thítȟuŋwaŋ"), they are one of the three Sioux tribes of Plains. Their current lands are in North and South Dakota. They speak "Lakȟótiyapi"—the Lakota language, the westernmost of three closely related languages that belong to the Siouan language family.