Did you know?  
"Sioux Indians" is not what we call ourselves.  "Sioux" is a French rendering of the Ojibwa word, "treacherous snakes." And "Indians" is the mistaken identity Christopher Columbus gave us when he journeyed to America in 1492.  As a people, we prefer the term, "Lakota Natives."  
Lakota is a dialect of the Siouan Languages.  "Lakota" means "Alliance of friends."  The other dialects are Nakota and Dakota.