vigil (n.) Look up vigil at Dictionary.com
early 13c., "eve of a religious festival" (an occasion for devotional watching or observance), from Anglo-French and Old French vigile, from Latin vigilia "watch, watchfulness," from vigil "watchful, awake," from PIE *wog-/*weg- "be lively or active, be strong" (cf. Latin vigere "be lively, thrive," velox "fast, lively," vegere "to enliven;" Sanskrit vaja- "strength, speed;" Old English wacan "to wake up, arise," wacian "to be awake;" Old High German wahta "watch, vigil"). Meaning "watch kept on a festival eve" is from late 14c.; that of "occasion of keeping awake for some purpose" is recorded from 1711.