Longman Dictionary of Contemporary English
The Collaborative International Dictionary
lights-out \lights-out\ n. a signal to turn the lights out.
Syn: taps.
Wiktionary
n. 1 The time at night at which artificial lights are to be turn off, a curfew or bedtime. 2 The prescribed bedtime for persons living in a boarding school or staying in a hospital.
WordNet
n. a prescribed bedtime
(military) signal to turn the lights out [syn: taps]
Usage examples of "lights-out".
Mothcalled thus because the necrophiliac murderer who stirs after lights-out has trembling hands that flutter, and his skin is almost gray.
She would watch as lights-out fell across the river, bedtime for Uglyville, and know that she still had all night with Peris and her new friends, all the beautiful people she would meet.
Bridget Boone, in whose room a lot of the 16 and Unders used to congregate before lights-out, invited me to consider a couple of late-night bongs, as a kind of psychodysleptic Sominex, to help me sleep, perhaps, finally, all the way through a really unpleasant dream that had been recurring nightly and waking me up in medias for weeks and was beginning to grind me down and to cause some slight deterioration in performance and rank.
We marched off the demerits, kept our eyes down and seemed to submit to them, but at night, after lights-out, we often gathered to whisper and rejoice in our defiance.
There was a safety lamp that was kept burning in the stairwell at all times, even after lights-out.
For a whole week his small South Kensington flat would reverberate to the sound of twelve-year-old enthusiasms, to tales of prowess on the rugby field, jokes played on the French master, and the need for further supplies of jam and cake for illegal consumption after lights-out in the dormitory.