rector: [14] A rector is etymologically a ‘ruler’. The word comes via Old French rectour from Latin rēctor ‘governor’, a derivative of the verb regere ‘govern, rule’ (from which English gets regent, region, etc). It carried its original meaning with it into English, with reference both to Roman governors in the ancient world and to God as ‘ruler’ of the universe (Sir Matthew Hale in 1676 referred to God as the ‘great dispenser or permitter and rector of all the events in the world’), but by the 18th century it had largely become restricted to the more specialized senses ‘clergyman in charge of a parish’ and ‘head of a college’. => regent, regiment, region
rector (n.)
late 14c. (early 13c. in Anglo-Latin), from Latin rector "ruler, governor, director, guide," from rect-, past participle stem of regere "to rule, guide" (see regal). Used originally of Roman governors and God, by 18c. generally restricted to clergymen and college heads. Related: Rectorship.