UNTHINKABLE Synonyms: 66 Similar and Opposite Words

unthinkable

adjective

ˌən-ˈthiŋ-kə-bəl

Definition of unthinkable

as in incredible

too extraordinary or improbable to believe to most people it seemed unthinkable that such a gentle man could be guilty of such awful crimes

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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 unthinkable Even a few years ago, such a haul would have been unthinkable. — ABC News, 28 Oct. 2026 Gasly’s move triggered an unthinkable barrage of death threats not just against the French racer, but also his girlfriend and immediate family. — Jerry Perez, The Drive, 28 Oct. 2026 Before the start of the season, that would have seemed unthinkable. — Eben Novy-Williams, Sportico.com, 19 Oct. 2026 Just a few years ago, this scene of Jewish worshippers praying openly and vocally atop Jerusalem’s holiest of holy sites – known to Jews as the Temple Mount and to Muslims as the Al-Aqsa Mosque compound – would have been unthinkable. — Ilan Ben Zion, Christian Science Monitor, 14 Oct. 2026 See All Example Sentences for unthinkable

Recent Examples of Synonyms for unthinkable

Adjective

Achieving incredible data transmission speed The researcher fabricated the device using a 300-millimeter silicon-on-insulator manufacturing process.

— Rupendra Brahambhatt, Interesting Engineering, 24 Oct. 2026
This year’s incredible class of awardees includes Jason Bolden, Kellon Deryck, Molly Greenwald, Chris Horan, Amy Komorowski, Thuy Nguyen, Law Roach, and Trish Summerville.

— InStyle, InStyle, 24 Oct. 2026

Definition of incredible

Adjective

Friedman began her remarks by reminding the audience of von Furstenberg’s unlikely beginning, born in Brussels to a Holocaust survivor.

— Ariel Bielsky, Vogue, 24 Oct. 2026
Dahlia Scheindlin, a veteran pollster who works for left-of-center candidates and parties in Israel, speculated that the number of returning overseas voters was unlikely to be big enough to change the outcome of the election.

— Daniel Brook, New Yorker, 24 Oct. 2026

Definition of unlikely

Adjective

Cam asked her, incredulous that his talkative fiancée had nothing to say.

— Jason P. Frank, Vulture, 4 Nov. 2026
Some congressional Democrats were incredulous, saying the email might simply have been deleted and that the firm’s analysis did not explain why or how someone might have manufactured the message.

— New York Times, New York Times, 22 Oct. 2026

Definition of incredulous

Adjective

The problem has to do with how a set of equations that model the movement of fluids seems to imply solutions with infinite speed, which should be impossible.

— Rivka Galchen, New Yorker, 1 Nov. 2026
Camas coach Matt LeGrand — who's in an impossible position — would not comment on why.

— Matt Calkins OutKick, FOXNews.com, 1 Nov. 2026

Definition of impossible

Adjective

But the story of twentieth-century democracy from Watergate to the Pentagon Papers is inconceivable without print.

— Literary Hub, Literary Hub, 14 Oct. 2026
Technology, public taste and economic conditions all contributed to its once-inconceivable drastic makeover.

— Rick Nicita, HollywoodReporter, 30 Sep. 2026

Definition of inconceivable

Adjective

The history of organic abstraction that runs through Jean Arp and Henry Moore is unimaginable without the inner vitality of Brancusi’s rounded shapes.

— Michael Brenson, Vogue, 1 Nov. 2026
Built in Southern California, the Endeavour embodies the shuttle program’s technological ambition and diversity, while reminding visitors how cooperation can make the unimaginable possible.

— Laura Zornosa, Los Angeles Times, 28 Oct. 2026

Definition of unimaginable

Adjective

Dubbed 'Flash Charging,' this allows the Atto 8’s massive 115-kilowatt-hour battery to rocket from a 10% charge up to 70% capacity in an almost unbelievable five minutes.

— New Atlas, New Atlas, 17 Oct. 2026
What Zoe [Kazan] has done with Steinbeck’s East of Eden is just unbelievable.

— Brian Davids, HollywoodReporter, 14 Oct. 2026

Definition of unbelievable

Browse Nearby Words

untethers

unthinkable

unthinkably

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“Unthinkable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unthinkable. Accessed 7 Nov. 2026.

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Synonyms of unthinkable

adjective

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