vigil

Concise Oxford English Dictionary © 2008 Oxford University Press:
vigil /ˈvɪdʒɪl/

▶noun

• 1 a period of staying awake during the time usually spent asleep, especially to keep watch or pray.

• 2 (in the Christian Church) the eve of a festival or holy day as an occasion of religious observance.

  ■ (vigils) nocturnal devotions.

• 3 a stationary, peaceful demonstration in support of a cause.

– origin ME: via OFr. from L. vigilia, from vigil ‘awake’.