What does apparition mean?
The definition of apparition
Ap`pa*ri”tion, n.
Etym: [F. apparition, L. apparitio, fr. apparere. See Appear.]

1 The act of becoming visible; appearance; visibility. Milton. The sudden apparition of the Spaniards. Prescott. The apparition of Lawyer Clippurse occasioned much speculation in that portion of the world. Sir W. Scott.
2 The thing appearing; a visible object; a form. Which apparition, it seems, was you. Tatler.
3 An unexpected, wonderful, or preternatural appearance; a ghost; a specter; a phantom. “The heavenly bands . . . a glorious apparition.” Milton. I think it is the weakness of mine eyes That shapes this monstrous apparition. Shak.
4 (Astron.)
The first appearance of a star or other luminary after having been invisible or obscured; — opposed to occultation. Circle of perpetual apparition. See under Circle.