Merriam-Webster Collegiate Dictionary - epiphany

 noun  (plural -nies)  Etymology: Middle English epiphanie, from Anglo-French, from Late Latin epiphania, from Late Greek, plural, probably alteration of Greek epiphaneia appearance, manifestation, from epiphainein to manifest, from epi- + phainein to show — more at fancy  Date: 14th century  1. capitalized January 6 observed as a church festival in commemoration of the coming of the Magi as the first manifestation of Christ to the Gentiles or in the Eastern Church in commemoration of the baptism of Christ  2. an appearance or manifestation especially of a divine being  3.  a.  (1) a usually sudden manifestation or perception of the essential nature or meaning of something  (2) an intuitive grasp of reality through something (as an event) usually simple and striking  (3) an illuminating discovery, realization, or disclosure  b. a revealing scene or moment