a family of North American Indian languages formerly spoken in the WC U.S., central Canada, and parts of Virginia and the Carolinas: it includes Iowa, Mandan, Dakota, Crow, Hidatsa, Osage, etc.
designating or of this family of languages
- A large North American Indian language family spoken from Lake Michigan to the Rocky Mountains and southward to Arkansas as well as in South Carolina.
- A member of a Siouan-speaking people.
Origin of SiouanSiou(x) -an 1