A more thorough explanation:

Definition: Mainprise (mayn-prIz) is a legal term that refers to the delivery of a prisoner to a mainpernor, who is responsible for ensuring the prisoner's appearance in court on a specified date and time. It can also refer to a writ ordering the sheriff to release a prisoner after taking security for the prisoner's appearance.

Examples:

• John was arrested for theft and was released on mainprise, which meant that his friend, who acted as his mainpernor, was responsible for ensuring that John appeared in court on the specified date.
• The judge issued a writ of mainprise, which ordered the sheriff to release the prisoner after taking security for his appearance in court.

These examples illustrate how mainprise was used in the past to ensure that prisoners appeared in court. It was a way to ensure that justice was served and that the accused had a fair trial. Today, mainprise is not commonly used, as there are other methods of ensuring that prisoners appear in court, such as bail.