Dictionary.net

In French law. An officer of the imperial court who either personally or by his deputy prosecutes every one who is accused of a crime according to the forms of French law. His functions appear to be confined to preparing the case for trial at the assizes, assisting in that trial, demanding the sentence in case of a conviction, and being present at the delivery of the sentence. He has a general superintendence over the officers of police and of the juges d'instruction, and he requires from the procureur du roi a general report once In every three months. Brown.