apparition (n.) Look up apparition at Dictionary.com
c.1500, "unclosing" (of Heaven), from Anglo-French aparicion, Old French apparition, aparoison (15c.), used in reference to the Epiphany (revealing of Christ child to the Wise Men), from Late Latin apparitionem (nominative apparitio) "an appearance," also "attendants," in classical Latin "service, servants," noun of action from past participle stem of apparere "appear" (see appear). Meaning "ghost" first recorded c.1600; the shade of sense differentiation between appearance and apparition is that the latter tends to be unexpected or startling.