xī​dēng

lights out

熄灯 (熄燈) xī​dēng
lights out verb
the designated time for lights to be turned off, especially in a shared living environment like a dormitory

School regulations state that it's lights out at 11:00 PM sharp.

extinguish verb
to turn out or put out the lights

Please remember to turn off the lights before leaving the room.

Frequency

Movie subtitles
2.62 per million appears in 1% of films
Written text
1.39 per million

Sources

Definitions
CC-CEDICT