Ablution refers to washing one's body. It could refer to having a daily bath and also as part of a special religious or ceremonial ritual.
Absolution is a noun. Meanings: forgiveness; pardon; release; freedom; liberty. It is used in the sense of being freed from some kind of guilt or an act of sin.
Examples of Ablution:
1. It is necessary to have a daily ablution in order to maintain good hygiene.
2. The priest began the puja only after an ablution.
3. The temple authorities decided to set up facilities for ablution for the out-station devotees.
Examples of Absolution:
1. On visiting the church, Jacob got absolution from the priest and no longer felt guilty.
2. Martha's mother reminded her daughter to get the priest's absolution after Mass.
3. A separate day was demarcated for absolution at the local church.