late 14c. (mid-13c. as a surname), "shepherd," also "spiritual guide, shepherd of souls," from Old French pastor, pastur "herdsman, shepherd" (12c.), from Latin pastorem (nominative pastor) "shepherd," from pastus, past participle of pascere "to lead to pasture, set to grazing, cause to eat," from PIE root *pa- "to feed; tend, guard, protect." The spiritual sense was in Church Latin (e.g. Gregory's "Cura Pastoralis"). The verb in the Christian sense is from 1872.