Sioux Siouan • sip · · · Info · Definitions · Characters · · Sioux · · Text Latin · · Script 5 · · Length Definitions · · · (noun) 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. Synonyms: Siouan. · · Noun Definition 1 Characters · · S latin capital letter s U+0053 i latin small letter i U+0069 o latin small letter o U+006F u latin small letter u U+0075 x latin small letter x U+0078