khagan /kɑˈɡɑn/ noun1 •(historical) A khan of khans, a ruler of a khaganate; (the holder of) an imperial rank used among certain Turkic and Mongolian peoples, equal in status to an emperor.As early as the year 740 A.D., one of the Khazar kaghans had turned to Constantinople for a missionary versed in Christian law. — 1988 formskhagans
