When the word epiphany was first used in English in the middle of the fourteenth century, it specifically referred to a festival in early January commemorating the manifestation of Christ to the Gentiles (at the time, it was always capitalized, and occasionally spelled Epyphany, Epiphanie, or Epiphanye). This had the same meaning as Old French epiphanie and Latin epiphania, and traces to the Ancient Greek word for "divine manifestation", epiphaneia. Eventually, around the 1660s, English started using that older definition to refer to manifestations of any deity, and it was eventually figuratively extended to mean "realization". Finally, epiphaneia contains the prefix epi-, meaning "upon", and the root phainein, meaning "show" or "shine".
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.