regime (n.)

"system of government or rule," 1792, from French régime, from Old French regimen (14c.), from Latin regimen "rule, guidance, government, means of guidance, rudder," from regere "to direct, to guide" (from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule"). Earlier "course of diet, exercise," late 15c. In French, l'ancien régime refers to the system of government before the revolution of 1789.