simple past tense and past participle of reform
"After years of trouble, he finally became a reformed man who never missed work again."
of or relating to the body of Protestant Christianity arising during the Reformation; used of some Protestant churches especially Calvinist as distinct from Lutheran
"Dutch Reformed theology"
Corrected; amended; restored to purity or excellence; said, specifically, of the whole body of Protestant churches originating in the Reformation, or, in a more restricted sense, of those who separated from Martin Luther on the doctrine of consubstantiation, etc., and carried the Reformation, as they claimed, to a higher point.
"The congregation split into a Reformed group that adopted stricter worship practices distinct from their Lutheran neighbors."
Of the Protestant movement typically associated with John Calvin, as separated from the Lutheran Church to pursue more extensive reformation.