Source : Webster's Revised Unabridged Dictionary (1913)

Tartar \Tar"tar\, n.
   1. [Per. T[=a]t[=a]r, of Tartar origin.] A native or
      inhabitant of Tartary in Asia; a member of any one of
      numerous tribes, chiefly Moslem, of Turkish origin,
      inhabiting the Russian Europe; -- written also, more
      correctly but less usually, {Tatar}.

   2. A person of a keen, irritable temper.

   {To catch a tartar}, to lay hold of, or encounter, a person
      who proves too strong for the assailant. [Colloq.]

Source : WordNet®

Tatar
     n 1: a member of the Mongolian people of central Asia who invaded
          Russia in the 13th century [syn: {Tartar}, {Mongol Tatar}]
     2: a member of the Turkic-speaking people living from the Volga
        to the Ural Mountains (the name has been attributed to
        many other groups)
     3: the Turkic language spoken by the Tatar people living from
        the Volga to the Ural Mountains