late 14c., "spiritual guide, ecclesiastic responsible for the spiritual welfare of those in his charge; parish priest," from Medieval Latin curatus "one responsible for the care (of souls)," from Latin curatus, past participle of curare "to take care of" (see cure (v.)). Church of England sense of "paid deputy priest of a parish" first recorded 1550s.
late 13c., person (late 12c. as a surname), "parish priest" (later often applied to a clergyman in general), from Anglo-French and Old French persone "curate, parson, holder of Church office" (12c.), from Medieval Latin persona "parson" (see person). The reason for the ecclesiastical use is obscure; it might refer to the "person" legally holding church property, or it may be an abbreviation of persona ecclesiae "person of the church." The shift to a spelling with -a- begins late 13c. in surnames. Related: Parsonic. Parson's nose "the rump of a fowl" is attested by 1834.