Tartar

noun

• a member of the combined forces of central Asian peoples, including Mongols and Turks, who under the leadership of Genghis Khan conquered much of Asia and eastern Europe in the early 13th century, and under Tamerlane (14th century) established an empire with its capital at Samarkand. See also Tatar.
• (tartar) a harsh, fierce, or intractable person: my new Company Commander is a horrible tartar