1. An action or a behavior that suggests sorrow or regret for a serious transgression: Andrew went to church every day as a penance for having taken a book from the bookstore without paying for it.

Shawn's penance for shoplifting in the grocery store was to write an essay on the social costs of shoplifting.

2. A sacramental rite involving contrition, confession of sins to a priest, the acceptance of penalties, and absolution: The pastor led the rite of penance for those in the congregation who attended.