noun
(law, historical) A writ directed to the sheriff, commanding him to take sureties, called mainpernors, for the prisoner's appearance, and to let him go at large.
(law, historical) Deliverance of a prisoner on security for his appearance at a day.
verb
(transitive, law) To allow (a prisoner) to go at large, on his finding sureties, or mainpernors, for his appearance on a given day.