means A period of staying awake to keep watch, pray, or honor someone — often through the night, when sleep would be easier.

from From Latin 'vigilia,' a wakeful watch, rooted in 'vigil' meaning awake or alert — a cousin of 'vigor,' 'vigilant,' and the verb 'vegere,' to be lively. It entered English through Old French as the night-watch kept before a religious feast, when the faithful held off sleep to pray. The word still carries that ache of forced wakefulness — to keep a vigil is to refuse, for love or duty, the rest your body is begging for.