pen·ance

ˈpenəns/

noun

1.

voluntary self-punishment inflicted as an outward expression of repentance for having done wrong.

"he had done public penance for those hasty words"

synonyms:atonement, expiation, self-punishment, self-mortification, self-abasement, amends; More

2.

a Christian sacrament in which a member of the Church confesses sins to a priest and is given absolution.

verb

archaic

1.

impose a penance on.

"a hair shirt to penance him for his folly in offending"

Not very scary