A more thorough explanation:

Mainpernable (mayn-pər-nə-bəl) is an adjective used in law to describe something that is capable of being bailed or released on the surety of a mainpernor. A mainpernor is someone who takes responsibility for a prisoner's appearance in court on a specified date and time.

• The accused was deemed mainpernable and released on bail.
• The judge granted the defendant's request for a writ of mainprise, ordering the sheriff to release him on the surety of a mainpernor.

These examples illustrate how the term mainpernable is used in the context of law to describe the ability to be released on bail or the responsibility taken by a mainpernor for a prisoner's appearance in court.