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. )

Explanation

In many religions, doomsday is the end of the world and the moment of final judgment. In your everyday life, doomsday might be the date of the final exam in your math class. Doomsday means utter catastrophe, in both religious and secular contexts. Many faiths believe in a literal doomsday, when life as we know it will come to an end. For centuries people have attempted to predict when this will occur, with the most recent guesses including 2011, 2012, and 2021. Generally, a doomsday scenario is any event that could cause human extinction, like catastrophic climate change or an asteroid impact. The Germanic root of doomsday means "judgment day."

Example Sentences

Disney showcased the first proper trailer for the long-awaited next Avengers film, Avengers: Doomsday, as the conference closed on Thursday.

From BBC • Apr. 17, 2026

Modeling it on the Bulletin of the Atomic Scientists nuclear-destruction warning Doomsday Clock, he called it the Zero-Day Clock.

From The Wall Street Journal • Apr. 14, 2026

Wolfsthal is among experts involved in the "Doomsday Clock" meant to symbolize how near humanity is to destruction.

From Barron's • Feb. 1, 2026

"There are plenty of projects we can't really reveal," he told AFP, but confirmed the studio will be working on the Marvel blockbuster "Avengers: Doomsday" and the second season of "Monarch."

From Barron's • Jan. 31, 2026

With Richardson’s curve and the simplest extrapolation for the future growth of the human population, the two curves do not intersect until the thirtieth century or so, and Doomsday is deferred.

From "Cosmos" by Carl Sagan