A more thorough explanation:

IDONEUM SE FACERE; IDONEARE SE

Idoneum se facere; idoneare se means "to make oneself sufficient; to clear oneself" in Law Latin. In history, it was used to describe the act of purging oneself, by oath, of a crime that one is accused of committing.

During the medieval period, if someone was accused of a crime, they could clear themselves by taking an oath of innocence. This was known as idoneum se facere or idoneare se.

For example, if someone was accused of theft, they could swear an oath of innocence in front of witnesses. If the oath was accepted, the accused would be cleared of the crime and would not face punishment.

Another example is the ordeal by fire or water. In this practice, the accused would have to hold a red-hot iron or plunge their hand into boiling water. If their wounds healed quickly, it was believed that God had intervened and declared them innocent.

These examples illustrate how idoneum se facere or idoneare se was used to clear oneself of a crime. It was a way for people to prove their innocence and avoid punishment.