Webster's Revised Unabridged Dictionary · 1913

Mainpernor

Mainpernor , noun

[Old French main hand + pernor, for preneor, a taker, French preneur, from prendre to take.]

(Law) A surety, under the old writ of mainprise, for a prisoner's appearance in court at a day.

Mainpernors differ from bail in that a man's bail may imprison or surrender him before the stipulated day of appearance; mainpernors can do neither; they are bound to produce him to answer all charges whatsoever.