apparition

Meanings

1. An act of becoming visible; appearance; visibility.
2. The thing appearing; a visible object; a form.
3. An unexpected, wonderful, or preternatural appearance; especially, one by a ghost, phantom, or suchlike; the entity itself.
4. The first appearance of a star or other luminary after having been invisible or obscured; opposed to occultation.
5. A period of consecutive days or nights when a particular celestial body may be observed, beginning with the heliacal rising of the body and ending with its heliacal setting.

Etymology

From Middle French apparition, from Latin apparitio, from appareo.