Definition of "Apparition" :

noun: an act of appearing or becoming visible unexpectedly

"Natives were amazed at the apparition of this white stranger."

noun: something existing in perception only

"A ghostly apparition at midnight."

noun: the appearance of a ghostlike figure

"I was recalled to the present by the apparition of a frightening specter."

noun: a ghostly appearing figure

"We were unprepared for the apparition that confronted us."