Definition from Wiktionary, the free dictionary
Related to vigor, and more distantly compare vis and vital, from similar Proto-Indo-European roots and meanings (lively, power, life), via Latin. For use of “live, alive” in sense “watching”, compare qui vive.
vigil (plural vigils)
- An instance of keeping awake during normal sleeping hours, especially to keep watch or pray.
- A period of observation or surveillance at any hour.
- His dog kept vigil outside the hospital for eight days while he was recovering from an accident.
- The eve of a religious festival in which staying awake is part of the ritual devotions.
- A quiet demonstration in support of a cause.
- The protesters kept vigil outside the conference centre in which the party congress was being held.
period of observation or surveillance
eve of a religious festival