doomsday

American  

[doomz-day] / 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.

---

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

---

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

See Examples For:

doomsday

Nvidia CEO Jensen Huang has described warnings that AI could lead to humanity's extinction by the next decade as "doomsday narratives".

From BBC ● Sep. 21, 2026

The vice president’s words sound good — like a rap on the knuckles of the tech billionaires who can’t stop claiming they’re building doomsday devices.

From Salon ● Sep. 20, 2026

“That 10% number is not based on research…there’s no scientific validity to that,” Bhadelia said of the Anthropic researcher’s doomsday prediction.

From MarketWatch ● Sep. 19, 2026

Investors piled back into the dollar—and out of gold—as a deterioration in the Middle East conflict and tech leaders’ doomsday warnings about AI soured risk sentiment.

From The Wall Street Journal ● Sep. 15, 2026

You probably expected a thousand words on gravity or the four laws of thermodynamics, not a journal recounting the last 144 days of my life—possibly of all life—interspersed with crazy doomsday scenarios.

From "We Are the Ants" by Shaun David Hutchinson