Appropriate Word of the Day:

apparition \ap-uh-RISH-un\, noun: 1. A ghost; a specter; a phantom.
2. The thing appearing; the sudden or unexpected appearance of something or somebody.
3. The act of becoming visible; appearance; visibility.
4. (Astronomy) The first appearance of a star or other luminary after having been invisible or obscured; -- opposed to occultation.

And a bit of trivia to accompany it:
Today is Halloween. In modern times, it is the occasion for pranks and for children requesting treats or threatening tricks. The term is short for "All Hallow Even," the evening preceding All Saints' Day, which at one time was called Allhallows. In the old Celtic calendar, the year began on November 1, so the last evening of October was called "old-year's night." It was considered the night of the witches, apparitions, and sinister spirits of all kinds, and it influenced the Christian festival of All Hallows' Eve.

Happy Halloween!