Late Middle English; earliest use found in John Lydgate (c1370–c1449), poet and prior of Hatfield Regis. From Middle French reformateur, French réformateur magistrate charged with reproaching officials who commit abuses of the law, person who re-establishes or restores a country and its etymon classical Latin reformātor person who moulds or reshapes, in post-classical Latin also person who restores or renews, person who amends, reformer (15th cent. in British sources; from reformāt-, past participial stem of reformāre + -or. Compare Old Occitan reformador person who corrects or reforms something, magistrate charged with reproaching officials who commit abuses of the law, German Reformator reformer, (also specifically) leader of the Reformation.