unhappening

/AH0 N HH AE1 P AH0 N IH0 NG/
verb
  1. 1

    To cease to have happened; to undo itself.

    โ€œI wish everything that happened between us could unhappen, and we could start again.โ€

noun
  1. 1

    A happening that fails to occur; a nonevent.

Source: https://en.wiktionary.org/wiki/unhappen, https://en.wiktionary.org/wiki/unhappening