Definitions of Tatar:

• noun:   the Turkic language spoken by the Tatar people living from the Volga to the Ural Mountains
• noun:   a member of the Turkic-speaking people living from the Volga to the Ural Mountains (the name has been attributed to many other groups)
• noun:   a member of the Mongolian people of central Asia who invaded Russia in the 13th century
• name:  A surname (very rare: popularity rank in the U.S.: #34587)