unthinkable

adjective

un·​think·​able ˌən-ˈthiŋ-kə-bəl 

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 

noun

unthinkably

ˌən-ˈthiŋ-kə-blē 

adverb

Synonyms

• fantastic
• fantastical
• implausible
• inconceivable
• incredible
• incredulous
• unbelievable
• uncompelling
• unconceivable
• unconvincing
• unimaginable

Examples of unthinkable in a Sentence

to most people it seemed unthinkable that such a gentle man could be guilty of such awful crimes

Recent Examples on the Web

The financial implications of missing out on qualification to the Champions League are unthinkable for Juve, who already experienced that exact outcome under Max Allegri in 2022/2023. —Adam Digby, Forbes, 23 Mar. 2025

Not long ago, such a stance by a U.S. president would have been unthinkable, Nilsson-Wright says. —Scott Neuman, NPR, 22 Mar. 2025

He's found in Elon Musk the kind of person who has the drive, the toughness, the intelligence to really fundamentally take on the 'deep state' and change it in ways that would normally be unthinkable. —Robert Costa, CBS News, 16 Mar. 2025

Was this one of those days for an unthinkable upset? —Dom Amore, Hartford Courant, 9 Mar. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing unthinkable

• the unthinkable

Rhymes for unthinkable

• thinkable

Kids Definition

unthinkable

adjective

un·​think·​able ˌən-ˈthiŋ-kə-bəl 

ˈən-

: not to be thought of or considered as possible

unthinkable cruelty