apparitor

noun2

1. •
   A messenger or officer who serves the process of an ecclesiastical court.

   • a monition be awarded to an apparitor, to summon a man — 1797
2. •
   (historical) An officer who attended magistrates and judges to execute their orders.

   • Before any of his apparitors could execute the sentence, he was himself summoned away by a sterner apparitor to the other world. — 1857