sioux(n = noun.person) siouan - a member of a group of North American Indian peoples who spoke a Siouan language and who ranged from Lake Michigan to the Rocky Mountains;
is a kind of buffalo indian, plains indian
has particulars: biloxi, catawba, crow, dakota, dhegiha, gros ventre, hidatsa, iowa, ioway, missouri, ofo, oto, otoe, eastern sioux, santee, santee dakota, santee sioux, lakota, teton, teton dakota, teton sioux, tutelo, winnebago, crazy horse, tashunca-uitco, rain-in-the-face
Derived form adjective siouan₁

   A nation of American Indians; see Dakotas. [1913 Webster]

sioux, n. & adj.
--n. (pl. same)
1 a member of a group of N. American Indian peoples.
2 the language of this group.
--adj. of or relating to this people or language.

Derivative:
Siouan adj. & n.

Etymology:
F f. a native name

big sioux river, eastern sioux, little sioux river, santee sioux, sioux city, sioux falls, sioux state, teton sioux