What action does "expiate" refer to?

The term "expiate" specifically refers to the act of making amends or atoning for one's guilt or wrongdoing. It involves actions that seek to alleviate guilt by providing some form of penance or compensation for an offense. This concept is often used in contexts where an individual feels remorse for their actions and seeks to reconcile that guilt through various means.

In contrast, the other options do not accurately encapsulate the meaning of "expiate." For example, to expel or remove involves a different action entirely, focusing on elimination rather than atonement. Lending support does not relate to guilt or repentance but rather to providing assistance. Forgiving another carries its own connotation, focusing on the act of pardoning someone else's wrongs rather than one's own guilt. Thus, the correct understanding of "expiate" directly connects to the notion of relieving one's own guilt through contrition or reparative actions.