- a former territory in the United States: divided into the states of North Dakota and South Dakota in 1889.
- North Dakota or South Dakota.
- the Dakotas, North Dakota and South Dakota.
- Also called Sioux. a member of the largest tribe of the Siouan stock of North American Indians, who originally occupied Minnesota and Wisconsin and later migrated westward to the Great Plains.
- Santee(defs 3, 4).
- a Siouan language spoken by the Dakota and Assiniboin Indians.
- a former territory of the US: divided into the states of North Dakota and South Dakota in 1889
1809, name of a group of native peoples from the Plains states speaking a Siouan language, from Dakota dakhota “friendly” (the name often is translated as “allies”). Recorded by Lewis and Clark (1804) as Dar co tar; in western dialects of the Teton subgroup, Lakota, Lakhota; in Assiniboine dialect, Nakota, Nakhota.