Custos
The Cyclopedic Law Dictionary · Walter A. Shumaker and George Foster Longsdorf; ed. James C. Cahill · 1922
The Cyclopedic Law Dictionary
A custodian, guard, keeper, or warden; a magistrate. pleas, whose duty it is to receive and keep all the writs returnable to that court, and put them upon file, and also to receive of the prothonotaries all records of nisi prius, called posteas.
Blount.
An officer in the king's bench, having similar duties. Cowell; Termes de la Ley. The office is now abolished.