The act of expiation is a way to atone for something you did that was wrong. It was originally used in a religious context, with expiation the way a person could gain forgiveness from a god.
If you’ve ever tried to make up for something you did wrong, then you understand the notion of expiation. The idea of atonement stretches across all religions, from Judaism’s Yom Kippur (Day of Atonement) to perhaps the most famous example of expiation, the Christian doctrine of Christ dying to absolve the world’s sins. You definitely don’t need to be religious to seek expiation. People who commit crimes and even make small mistakes seek expiation every day.
compensation for a wrong
the act of atoning for sin or wrongdoing (especially appeasing a deity)