Tumen or Tümen ("unit of ten thousand"; Mongolian: Түмэн, Tümen) was a part of the decimal system used by Turkic and Mongol peoples to organize their armies. Tumen is an army unit of 10,000 soldiers. Tumen was incorporated into the Mongolian language from the Uyghur language and is also used in the Mongolian language as another word for "very many".
The word "Tumen" was established by Mete Khan in the memory of his father, Touman.
Read more about Tumen: Genghis Khan's Organization, Magyar Military Organization of The Conquest Era, In Modern Armies