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."