doomsday

American  

[doomz-dey] / ˈdumzˌdeɪ /

noun

1. Theology. the day of the Last Judgment, at the end of the world.

2. any day of judgment or sentence.

3. nuclear destruction of the world.

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adjective

1. given to or marked by forebodings or predictions of impending calamity; especially concerned with or predicting future universal destruction.

   the doomsday issue of all-out nuclear war.

2. capable of causing widespread or total destruction.

   doomsday weapons.

doomsday British  

/ ˈduːmzˌdeɪ /

noun

1. (sometimes capital) the day on which the Last Judgment will occur

2. any day of reckoning

3. (modifier) characterized by predictions of disaster

   doomsday scenario

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Etymology

Origin of doomsday

First recorded before 1000; Middle English domes dai, Old English dōmesdæg “Judgment Day”; equivalent to doom ( def. ) + 's ¹ ( def. ) + day ( def. )

Example Sentences

The Treasury’s report should be understood as a warning light, not a doomsday clock.

From Barron's • Mar. 31, 2026

“If anything, we’re drenched in the legacy of this music. We’re optimists. I’m not ran by no doomsday clock. When we perform shows, people say, ‘You give me hope.

From Los Angeles Times • Mar. 31, 2026

One of them, XPrize & Singularity University founder and chair Peter H. Diamandis, just launched a $3.5 million fund to promote optimistic sci-fi films to counter the AI doomsday narrative.

From Salon • Mar. 26, 2026

Also read: The ‘smart money’ fled software stocks after that viral AI doomsday report.

From MarketWatch • Mar. 20, 2026

She’s probably holed up in the house like it’s doomsday.

From "The Hate U Give" by Angie Thomas