Pronunciation: (du-kō'tu),[key] —n. 1. a former territory in the United States: divided into the states of North Dakota and South Dakota 1889.
2. North Dakota or South Dakota.
3. the Dakotas,North Dakota and South Dakota.
4. 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.
5. Santee (defs. 3, 4).
6. a Siouan language spoken by the Dakota and Assiniboin Indians.