lights out

American  

noun

1. Chiefly Military. a signal, usually by drum or bugle, that all or certain camp or barracks lights are to be extinguished for the night.

2. bedtime.

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lights out British  

noun

1. the time when those resident at an institution, such as soldiers in barracks or children at a boarding school, are expected to retire to bed

2. a fanfare or other signal indicating or signifying this

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Etymology

Origin of lights out

First recorded in 1865–70

Example Sentences

"It means we can potentially design drugs that target the parasite's ARK1 specifically, turning the lights out on malaria without harming the patient."

From Science Daily • Mar. 5, 2026

The strategy shot the lights out when the housing and dotcom bubbles burst.

From The Wall Street Journal • Feb. 19, 2026

It could be a long, slow descent with the lights out on an RAF jet, or a rapid, corkscrew down in a C-130 transport plane.

From BBC • Jan. 23, 2026

Your firm’s IPO ETF has been relatively flat this year while the International IPO ETF is shooting the lights out, with a gain of nearly 40%.

From Barron's • Nov. 14, 2025

A dozen times or more, they unearthed the TV from behind the toolshed, late at night, with the lights out and quilts pinned over the windows.

From "A Thousand Splendid Suns" by Khaled Hosseini

Related Words

• collapse
• departure
• dissolution
• downfall
• extinction
• failure
• passing
• termination