penance

A voluntary self-imposed punishment for a sinful act or wrongdoing. It may be intended to serve as reparation for the act.

Quoth he, "The man hath penance done, / And penance more will do."

A sacrament in some Christian churches that involves penitence (remorse plus restitution via prayer).

Any instrument of self-punishment.

repentance

pain; sorrow; suffering

To impose penance; to punish.

She seem'd, at once, some penanced lady elf, / Some demon mistress, or the demon's self.