lights-out

• IPA^(key): /ˈlaɪts.aʊt/

• Audio (US):

  (file)

lights-out (uncountable)

1. The time at night at which artificial lights are to be turned off, a curfew or bedtime.
2. The prescribed bedtime for persons living in a boarding school or staying in a hospital.

   We were all expected to be in bed by lights-out.

• out like a light
• curfew