Source : WordNet®

Siouan
     adj : of or relating to the Sioux people or their language and
           culture

Siouan
     n 1: 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 [syn: {Sioux}]
     2: a family of North American Indian languages spoken by the
        Sioux [syn: {Siouan language}]