n ( pl Sioux )
a member of a Native-American people, also called the Dakota people, many of whom live in South Dakota on reservations (= land given and protected by the US government). The Sioux were originally an association of seven groups on the Great Plains where, led by Sitting Bull and Crazy Horse , they fought the US Army. They defeated General George Custer at the Battle of Little Bighorn but lost their final battle at Wounded Knee .