1. education student assisting with discipline: a student who is given some authority over other pupils in matters of discipline in a private school
2. christianity senior master at Jesuit school: a senior master or administrator with special responsibilities at a Jesuit school or college
3. police French chief of police: the head of a French police force, especially in Paris
4. public administration high-ranking administrative official: the highest official in an administrative district department or former territorial possession of France or in an administrative region of Italy
5. ancient hist Roman magistrate or commander: a senior administrative or military official in ancient Rome
[14th century. Via French< Latin praefectus "overseer" < past participle of praeficere "set over" < facere "make"]
