vigil

Etymology

From Middle English vigile (“a devotional watching”), from Old French vigile, from Latin vigilia (“wakefulness, watch”), from vigil (“awake”), from Proto-Indo-European *weǵ- (“to be strong, lively, awake”). See also wake, from the same root. 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.

noun

1. An instance of keeping awake during normal sleeping hours, especially to keep watch or pray.
   Eventually the body trade grew so reckless that relatives took to holding graveside vigils, lest their loved ones disappear in the night. 2016, Colson Whitehead, The Underground Railroad, Fleet (2017), page 165
2. 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.
3. The eve of a religious festival in which staying awake is part of the ritual devotions.
4. A quiet demonstration in support of a cause.
   The protesters kept vigil outside the conference centre in which the party congress was being held.