The term rector in the widest ecclesiastical sense means "one who sets straight, guides, directs; a ruler, governor, director, guide, leader," from the Latin verb rego, regere, rexi, rectum, "to set straight, guide, direct". It has similar meanings, in governmental and academic spheres of administration. A female equivalent is rectoress, and the term and office of a rector are a rectorate.
The Latin adjective rectus, meaning "straight", derives from the same source as the verb rego, regere, rexi, rectum, to rule, set straight. Thus a "ruler" in English refers both to a king and a drawing instrument for producing straight lines. In a moral sense a rector has the function of keeping those under his authority on the "straight and narrow path" of correct religious ideology. In classical Latin a rector may be a ruler, director or naval steersman, from which sense is derived "governor", Latin gubernator, one who operates the gubernum, the "rudder" of a ship.
In ancient times bishops, as rulers of cities and provinces, especially in the Papal States, were called rectors, as were administrators of the patrimony of the Church (e.g. rector Siciliæ). The term 'Rector' was used by Pope Gregory