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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.

Just a year ago, the idea of commodity-sensitive energy companies reaching these valuations would have been unthinkable.

From MarketWatch • Mar. 25, 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

It is to ensure that the cost of starting one remains permanently unthinkable.

From The Wall Street Journal • Mar. 24, 2026

For a club like Tottenham, relegation in the modern era had always been completely unthinkable.

From The Wall Street Journal • Mar. 14, 2026

Deeper still, I can feel the cold of the earth replaced by heat until there are caverns of red-hot, then white-hot magma, swirling under unthinkable pressure.

From "Challenger Deep" by Neal Shusterman

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.