Definitions
1.NounAn act of becoming visible; appearance; visibility.
2.NounThe thing appearing; a visible object; a form.
3.NounAn unexpected, wonderful, or preternatural appearance; especially, one by a ghost, phantom, or suchlike; the entity itself."The region's economy is buoyed by tourism driven by past apparitions of the Virgin Mary.; The attic is said to be haunted by the ghostly apparition of a young girl who died there.; He spoke to the apparition, and although its lips did not move, he somehow heard its reply."
4.NounThe first appearance of a star or other luminary after having been invisible or obscured; opposed to occultation.
5.NounA 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.