Why were the Sioux Indian Tribe named the Sioux Indian Tribe?

the Sioux Indian tribes actually refer to three distinct groups of Plains Natives...all share similar dilects of the siouan language..."Referred to collectively by outsiders as Sioux, a French rendition of the Ottawa name na•towe•ssiwak, meaning 'enemy,' the Sioux call themselves Lakota or Dakota, depending on dialect, signifying 'allies.'"

edited out > well they were called the Indians but then later changed the name to SIOUX cause there was one reason why this name has been changed tho SIOUX!<