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Definitions

unthinkable

[uhn-thing-kuh-buhl] / ʌnˈθɪŋ kə bəl /
ADJECTIVE
incredible, unusual
Synonyms
STRONGEST
absurd extraordinary illogical implausible impossible improbable inconceivable preposterous rare unbelievable uncommon unimaginable unlikely unreasonable
WEAK
beyond belief beyond possibility exceptional incogitable insupportable out of the question outlandish singular unique unordinary
Antonyms
STRONGEST
believable cheap common familiar imaginable likely logical normal ordinary plausible possible probably rational reasonable regular sensible tenable usual
WEAK
conceivable credible

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Out stepped a visitor whose arrival would have been unthinkable a decade ago.

From The Wall Street Journal • Apr. 15, 2026

Completely free trade makes sense only in a world where disruption is unthinkable.

From The Wall Street Journal • Apr. 15, 2026

Supporters love the "madman theory" for its ability to keep opponents off guard and pull off previously unthinkable achievements.

From BBC • Apr. 8, 2026

"And it is unthinkable - but those thoughts demand to be thought and I will not hide my face. But she needs to come home now."

From BBC • Mar. 25, 2026

And in the open, unthinkable as it was, the man in black was superior.

From "The Princess Bride" by William Goldman