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.
- Rhymes: -ɪdʒəl
vigil (plural vigils)
- A watch kept during normal sleeping hours, especially over the body of a recently deceased or dying person.
- A period of observation or surveillance.
- The eve of some religious festival in which staying awake is part of the ritual devotions.
Related terms 
From Proto-Indo-European *weg- (“to be strong”).