unthinkable

adjective

un·​think·​able ˌən-ˈthiŋ-kə-bəl How to pronounce unthinkable (audio)
Synonyms of unthinkablenext
1
: not capable of being grasped by the mind
2
: being contrary to what is reasonable, desirable, or probable : being out of the question
unthinkability
ˌən-ˌthiŋ-kə-ˈbi-lə-tē How to pronounce unthinkable (audio)
noun
unthinkably
ˌən-ˈthiŋ-kə-blē How to pronounce unthinkable (audio)
adverb

Synonyms of unthinkable

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Examples of unthinkable in a Sentence

to most people it seemed unthinkable that such a gentle man could be guilty of such awful crimes
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From 1968 to 1974, its Apollo program landed on the Moon six separate times, a pace that seems unthinkable today. — Frank Landymore, Futurism, 29 Oct. 2026 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 That would be unthinkable, unprecedented, a constitutional crisis. — Los Angeles Times, 23 Oct. 2026 See All Example Sentences for unthinkable

Word History

First Known Use

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of unthinkable was in the 15th century

Phrases Containing unthinkable

Rhymes for unthinkable

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unthinkability
unthinkable
unthinking
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Cite this Entry

“Unthinkable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unthinkable. Accessed 1 Nov. 2026.

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Kids Definition

unthinkable

adjective
un·​think·​able ˌən-ˈthiŋ-kə-bəl How to pronounce unthinkable (audio)
ˈən-
: not to be thought of or considered as possible
unthinkable cruelty
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