A more thorough explanation:

Term: Repudium
Definition: Repudium is a legal term that means the cancellation of a marriage engagement or marriage by either the man or the woman. In ancient Rome, if a man or woman wanted to end their engagement or marriage, they had to send a letter of repudiation to their partner. This letter was a formal way of ending the relationship. Repudium is similar to divorce, but it was used in ancient Rome instead of divorce.
Examples: If a man and woman were engaged to be married, but the man changed his mind and no longer wanted to marry the woman, he could send a letter of repudiation to her. This would cancel the engagement and end the relationship. Similarly, if a married couple wanted to end their marriage, they could send a letter of repudiation to each other. This would cancel the marriage and allow them to go their separate ways. These examples illustrate how repudium was used in ancient Rome to end relationships.