The term Siouan is the adjective denoting the "Sioux" Indians and cognate tribes. The word "Sioux" has been variously and vaguely used. Originally it was a corruption of a term expressing enmity or contempt, applied to a part of the plains tribes by the forest-dwelling Algonquian Indians. According to Trumbull, it was the popular appellation of those tribes which call themselves Dakota, Lakota, or Nakota ("Friendly," implying confederated or allied), and was an abbreviation of _Nadowessioux_, a Canadian-French corruption of _Nadowe-ssi-wag_ ("the snake-like ones" or "enemies"), a term rooted in the Algonquian _nadowe_ ("a snake"); and some writers have applied the designation to different portions of the stock, while others have rejected it because of the offensive implication or for other reasons. So long ago as 1836, however, Gallatin employed the term "Sioux" to designate collectively "the nations which speak the Sioux language,"(2) and used an alternative term to designate the subordinate confederacy—i.e., he used the term in a systematic way for the first time to denote an ethnic unit which experience has shown to be well defined. Gallatin’s terminology was soon after adopted by Prichard and others, and has been followed by most careful writers on the American Indians. Accordingly the name must be regarded as established through priority and prescription, and has been used in the original sense in various standard publications.(3) In colloquial usage and in the usage of the ephemeral press, the term "Sioux" was applied sometimes to one but oftener to several of the allied tribes embraced in the first of the principal groups of which the stock is composed, i.e., the group or confederacy styling themselves Dakota. Sometimes the term was employed in its simple form, but as explorers and pioneers gained an inkling of the organization of the group, it was often compounded with the tribal name as "Santee-Sioux," "Yanktonnai-Sioux," "Sisseton-Sioux," etc. As acquaintance between white men and red increased, the stock name was gradually displaced by tribe names until the colloquial appellation "Sioux" became but a memory or tradition throughout much of the territory formerly dominated by the great Siouan stock. One of the reasons for the abandonment of the name was undoubtedly its inappropriateness as a designation for the confederacy occupying the plains of the upper Missouri, since it was an alien and opprobrious designation for a people bearing a euphonious appellation of their own. Moreover, colloquial usage was gradually influenced by the usage of scholars, who accepted the native name for the Dakota (spelled Dahcota by Gallatin) confederacy, as well as the tribal names adopted by Gallatin, Prichard, and others. Thus the ill-defined term "Sioux" has dropped out of use in the substantive form, and is retained, in the adjective form only, to designate a great stock to which no other collective name, either