Sioux/suː/ Definition 1 of 2Pro Tip 1/3Cultural Respect Use 'Sioux' with respect, acknowledging its connection to indigenous peoples. She studied the Sioux's influential heritage. Pro Tip 2/3Pronunciation Pronounce 'Sioux' as 'soo', the 'x' is silent which can be confusing for learners. The Sioux are known for their horsemanship. Pro Tip 3/3Historical Sensitivity Be aware of the Sioux's historical struggles and current issues when discussing them. There was a Sioux-led protest yesterday.