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 of unthinkable

• incredible
• unlikely
• incredulous
• impossible
• inconceivable
• unimaginable
• unbelievable

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

In every way, such programs are unthinkable in Norway, a highly egalitarian society, in which wealth and resources are distributed evenly. —Don Riddell, CNN Money, 22 Feb. 2026

Restaurant Paul Bocuse A visit to Lyon without reserving a table at the fine dining palace of legendary chef Paul Bocuse is unthinkable for anyone with a passion for food. —John Brunton, Condé Nast Traveler, 21 Feb. 2026

For some, this means kicking off discussions, like whether to increase Europe’s own nuclear deterrent, that would have been unthinkable a decade earlier. —Daniel Depetris, Chicago Tribune, 19 Feb. 2026

Of course, such cooperation would be unthinkable today. —Anthony Crupi, Sportico.com, 16 Feb. 2026

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