According to the Armenian-Turkish linguist Sevan Nisanyan, the origin of the term "Efe" is either of Greek (efevos, 'young man with courage') or Turkic (eğe, ece, ebe, "big brother" in old Turkic) origin.[6] The origin of the term "Zeybek" is according to Nisanyan also not clear. According to Nisanyan it is either of Turkic or Arabic origin[7] Some sources claim that it evolved from sübek, sü meaning "army, soldiers" and bek meaning "lord (bey)" in old Turkic.