1. (n.) The act of reforming, or the state of being reformed; change from worse to better; correction or amendment of life, manners, or of anything vicious or corrupt; as, the reformation of manners; reformation of the age; reformation of abuses.

2. (n.) Specifically (Eccl. Hist.), the important religious movement commenced by Luther early in the sixteenth century, which resulted in the formation of the various Protestant churches.