Someone employed to manage another's business affairs; a steward; also, a lawyer who worked in courts of *canon law. The term was used in the 13c and later of the official today called 'churchwarden'. He was responsible for managing the funds for a parish church's fabric maintenance. In the north of England, the proctor was also known as 'kirkmaster' or 'church *grieve'.
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.