essoin

from The Century Dictionary.

• noun In old English law, an excuse for not appearing in court to defend an action on the day appointed for that purpose; the alleging of such an excuse.
• noun Excuse; exemption.
• noun One who is excused for non-appearance in court on the day appointed.
• In law, allowed for the appearance of suitors: an epithet applied to the first, three days of a term, now disused.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Eng. Law) An excuse for not appearing in court at the return of process; the allegation of an excuse to the court.
• noun obsolete Excuse; exemption.
• noun (Eng. Law) the first general return day of the term, on which the court sits to receive essoins.
• transitive verb (Eng. Law) To excuse for nonappearance in court.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb UK, law, transitive To excuse for failure to appear in court.