(1):

(v. i.) A religious service performed in the evening preceding a feast.

(2):

(v. i.) Hence, devotional watching; waking for prayer, or other religious exercises.

(3):

(v. i.) Abstinence from sleep, whether at a time when sleep is customary or not; the act of keeping awake, or the state of being awake, or the state of being awake; sleeplessness; wakefulness; watch.

(4):

(v. i.) Later, the day and the night preceding a feast.

(5):

(v. i.) Originally, the watch kept on the night before a feast.