Black's Law Dictionary (2nd edition)dictionaries

Mainpernor

In old practlce. A surety for the appearance of a person under arrest, who is delivered out of custody Into the hands of his ball. “Mainpernors” dif-fer from “ball” in that a mnn’s bail may imprison or surrender him up before the stipulated day of appearance; mainpernors can do neither, but are barely sureties for hls appearance at the day. Bail are only sureties that the party be answerable for the speclal matter for which they stipulate; mainpernors are bound to produce him to answer all charges whatsoever. 3 Bl. Comm. 128. other distinctions are made in tbe old books. See Cowell

Source: Black’s Law Dictionary 2nd Ed (1910)