An Etymological Dictionary of Astronomy and Astrophysics

A monarch who rules or reigns over an empire.

Etymology (EN): M.E., from O.Fr. empereor “emperor, leader, ruler,” from L. imperiatorem (nominative imperiator) “commander, emperor,” from p.p. stem of → imperare “to command.”

Etymology (PE): Parmâtyâr, from parmât, present stem of parmâtidan, → imperare, + suffix -yâr, as in šahryâr “sovereign, king,” hušyâr “sober, cautious, intelligent,” kušyâr “name of a physician; industrious” kâmyâr “happy, powerful,” and baxtyâr “fortunate, rich.”