eve

/iหv/
noun
  1. 1

    The day or night before, usually used for holidays, such as Christmas Eve.

  2. 2

    Evening, night.

  3. 3

    The period of time when something is just about to happen or to be introduced

    โ€œthe eve of a scientific discoveryโ€

Source: https://en.wiktionary.org/wiki/eve