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lights-out

noun \ ˈlīts-ˈau̇t \
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Definition of lights-out

1 : a command or signal for putting out lights
2 : a prescribed bedtime for persons living under discipline

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First Known Use of lights-out

1868

LIGHTS-OUT Defined for English Language Learners

lights-out

noun

Definition of lights-out for English Language Learners

  • : a time when people (such as soldiers, prisoners, or students) are required to turn out the lights and go to bed

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