atone
v.v. to make up for a mistake or a bad action. You do this by doing something good to show you are sorry.
v. to make amends for a wrong or a fault by performing a compensatory action. Often used in religious or moral contexts to describe the act of seeking forgiveness.
He tried to atone for his mistake by working extra hours.
The company spent years trying to atone for its environmental damage by investing in clean energy projects.
In many religious traditions, the act of atonement requires not only a sincere apology but also a significant change in one's behavior to demonstrate genuine remorse.
From atone (“reconciled”), from Middle English atone, attone, atoon (“agreed”, literally “at one”), equivalent to at + one. Compare Latin adūnō (“I unite, make one”) for the similar formation. Regarding the different phonological development of atone and one, see the note in one.