Tartars (originally Tatars), a name of no precise ethnological signification, used in the 13th century to describe the Mongolic, Turkish, and other Asiatic hordes, who, under Genghis Khan (q.v.), were the terror of Eastern Europe, and now bestowed upon various tribes dwelling in Tartary, Siberia, and the Asiatic steppes.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Tarsus * Tartarus