1,400 new words in our dictionary! — Parasocial, glow-up, promposal & more
1,400 new words in our dictionary! — More

cataclysmal

adjective

variants or cataclysmic
1
as in disastrous
bringing about ruin or misfortune a cataclysmal decision to plunge the nation into war

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms
2
as in devastating
causing or tending to cause destruction a cataclysmal landslide that virtually wiped out the village

Synonyms & Similar Words

Antonyms & Near Antonyms
3
as in turbulent
marked by sudden or violent disturbance the French Revolution was one of the great cataclysmal events in modern history

Synonyms & Similar Words

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of cataclysmal The simulations showed that moons smaller than 620 miles across were unlikely to retain an ocean after a cataclysmic impact. — Keith Cooper, Space.com, 27 Sep. 2026 Several of the researchers who spoke to NBC News said that humans could leverage AI systems to inflict cataclysmic damage well before recursive self-improvement materializes. — Jared Perlo, NBC news, 19 Sep. 2026 The diagnosis is cataclysmic, bringing Sandra’s career to an abrupt close. — Natalia Winkelman, Variety, 16 Sep. 2026 In 2026, how reasonable are fears that AI, either by escaping human control or through misuse by unscrupulous people, could cause a cataclysmic event or the downfall of civilization? — ABC News, 14 Sep. 2026 Rising global temperatures have made high-mountain areas across the globe more unstable—and the risks of cataclysmic events have increased. — Jackie Flynn Mogensen, Scientific American, 2 Sep. 2026 The mountains above had unleashed a cataclysmic, deluge that swept 62 miles (100 km) downstream, killing hundreds and burying entire communities in the worst natural disaster to hit Nepal in years. — Ross Adkin, CNN Money, 30 Aug. 2026 The effect of the wealth consolidation carefully, and secretly, orchestrated by the SEC and Big 10 has been not catastrophic to those not in these respective leagues, but at least cataclysmic. — Fort Worth Star-Telegram, 26 Aug. 2026 Barring a cataclysmic injury, all of this translates into an eventual Young contract extension. — Scott Fowler, Charlotte Observer, 30 July 2026
Recent Examples of Synonyms for cataclysmal
  1. disastrous
  2. devastating
  3. turbulent
  4. fatal
  5. destructive
  6. unfortunate
  7. catastrophic
Adjective
  • Still, by the time the meeting ended, aldermen had agreed the new terms made the disastrous 2008 privatization of the city’s once-public system a little bit better.
    — Jake Sheridan, Chicago Tribune, 24 Sep. 2026
  • Undeterred, the press has continued to publish damning reports about his chaotic management of the Pentagon at home and the US military’s disastrous conduct overseas.
    — Aidan McLaughlin, Vanity Fair, 24 Sep. 2026
Definition of disastrous
Adjective
  • Nearly a month after the first in a devastating string of beluga deaths at Shedd Aquarium, its officials Friday offered preliminary answers about what may have gone wrong.
    — Lila Hempel-Edgers, Chicago Tribune, 25 Sep. 2026
  • The memory has historically been prone to devastating boom-and-bust cycles.
    — Natasha Abellard, CNBC, 25 Sep. 2026
Definition of devastating
Adjective
  • These are bright and turbulent regions powered by central engine supermassive black holes with masses of millions or even billions of times that of the sun that are feeding on copious amounts of gas and dust.
    — Robert Lea, Space.com, 21 Sep. 2026
  • Iran has attended the General Assembly in various forms for decades, through turbulent times as well as moments of diplomatic progress.
    — Billy Stockwell, CNN Money, 21 Sep. 2026
Definition of turbulent
Adjective
  • In its statement, FARDC said an investigation to determine the actual circumstances and the exact causes of the fatal plane crash was already underway.
    — Angel Saunders, PEOPLE, 29 Sep. 2026
  • As flu season approaches, TikTokers are spreading a homemade elixir to supposedly boost the immune system that experts warn could in fact cause the fatal disease botulism.
    — Adam Kovac, Scientific American, 28 Sep. 2026
Definition of fatal
Adjective
  • But most destructive is the voice of Jamal’s stepdad, which is a negative, paranoid voice that tries to convince him to doubt the intentions of those around him.
    — Alex Ritman, Variety, 25 Sep. 2026
  • Such capabilities can potentially affect military intelligence, communications, and navigation without creating the debris associated with destructive anti-satellite missile tests.
    — Kaif Shaikh, Interesting Engineering, 25 Sep. 2026
Definition of destructive
Adjective
  • These unfortunate souls were supposed to stay in their birthplace, hoping church charity would sustain them.
    — Literary Hub, Literary Hub, 28 Sep. 2026
  • Artistic but flighty, Deborah ends up at her parents’ alma mater when an unfortunate incident gets her NYU Tisch School of the Arts acceptance rescinded.
    — Aramide Tinubu, Variety, 24 Sep. 2026
Definition of unfortunate
Adjective
  • An ugly game-ending arm injury suffered by Washington starting quarterback Jayden Daniels on the final play of the first half, which caused Fox Sports analyst Tom Brady to curse on air, had a catastrophic effect on the Commanders’ chances.
    — Fort Worth Star-Telegram, Fort Worth Star-Telegram, 21 Sep. 2026
  • These findings meaningfully raise the odds of either a massive settlement and licensing deal or, failing that, a Times victory at trial that would be catastrophic for the defendants and enormously remunerative for the plaintiff.
    — Michael Khouw, CNBC, 21 Sep. 2026
Definition of catastrophic

Browse Nearby Words

cataclysm
cataclysmal
cataclysms
See all Nearby Words

Cite this Entry

“Cataclysmal.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/cataclysmal. Accessed 29 Sep. 2026.

Copy Citation
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of argot

See Definitions and Examples »

Popular in Grammar & Usage

See More

Do You Need a New Language Peeve?

More Commonly Mispronounced Words

Merriam-Webster’s Great Big List of Words You Love to Hate

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?
See More

Popular in Wordplay

See More

7 Great Ways to Say 'Great'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

12 Lovely and Unusual Words for the Natural World

Why do we 'bury the lede?'
See More

Popular

See More

Do You Need a New Language Peeve?

7 Great Ways to Say 'Great'

The Longest Long Words List
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
image of the words cracker fly and sale arranged in a triangle with the word fire in the middle
Triple Play Quiz Find the word that pairs with each of the three g...
See All