To extinguish the guilt of by sufferance of penalty or some equivalent; to make complete satisfaction for; to atone for; to make amends for; to make expiation for; as, to expiate a crime, a guilt, or sin
If you expiate guilty feelings or bad behaviour, you do something to indicate that you are sorry for what you have done. It seemed that Alice was expiating her father's sins with her charity work. + expiation ex·pia·tion an often painful process of evaluation and expiation. to show you are sorry for something you have done wrong by accepting your punishment willingly, or trying to do something to improve what you did (past participle of expiare, from pius; PIOUS)