A Few Words About a Word…
In the introduction to "Black Elk: Holy Man of the Oglala," there is a discussion of the word "Sioux" which is an objectionable term to many Lakota/Dakotas:

"...'Sioux' was actually the shortened form of an Ottawa word 'Nadowessiwag' (spelled different ways within the literature), which meant 'little serpents.' The Iroquois apparently loomed as a larger threat to Ottawa existence and so were called 'Nadowe" or 'big serpents.'" And thus, Sioux came to signify "enemy."

Steltenkamp, Michael F.; Black Elk, Holy Man of the Oglala; University of Oklahoma Press: Norman & London, 1993.