The name is Chahta in Chahta anumpa, the Choctaw language. Choctaw is a fairly faithful English adaption of the word. No one is certain what the name means, but the origin narrative of the Choctaw and Chickasaw perhaps sheds some light on how these nations got their names. Both depict the Choctaw and the Chickasaw as once having been a unified tribe during their early migrations. Their movements were directed by the divination of prophet, using a sacred pole and medicine bag. If the prophet found the pole leaning in the morning, the tribe moved in that direction - if it stood straight, they had found their new homeland.

Soon after crossing the Mississippi, confusion arose. In the Chickasaw version, there was disagreement over whether the pole was standing straight or whether it was ever-so-slightly leaning eastward. Two factions arose. Those who thought the pole stood straight and that they should settle here were led by a man named Chiksa. Those who thought it continued to point eastward and that the tribe should therefore move on were led by a man named Chata. In the end, Chiksa and Chata came to a compromise and Chata's faction was allowed to carry on as they wished.

In another version of the story, this time from a Choctaw source, it seems Chiksa and Chata were both in agreement that the pole indicated that they should settle the area, but they both had wider notions of what constituted the area. Chiksa left with one group to explore for a suitable village site, and Chata left with another a few days later. Originally Chata intended on following Chiksa's party northward but a harsh blizzard blotted out all signs of Chiksa's movements, and Chata diverted his group to the southeast.

In either event, most Choctaw origin narratives pick up with what happens next for the Choctaw. They came to the site of Nanih Waiya (or, in some version, emerged from the earth here). They quickly set about constructing the earthwork, which became the epicenter of the early Choctaw nation.

Now whether the early leaders of the two nations were actually named Chata and Chiksa, or whether those characters were given those names later in the creation of a nation-building mythos is unknown. But no one's presented a better idea of where the names came from yet.