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

The median age of a first-time buyer is now 40—a number that would have been almost unthinkable a generation ago. —Nick Lichtenberg, Fortune, 17 Apr. 2026

While making music that has impacted the lives of countless fans, these young artists were facing unthinkable traumas that have followed many into adulthood. —Angela Andaloro, PEOPLE, 15 Apr. 2026

He is embroiled in unthinkable personal issues, pursuing legal action against his parents in a Philadelphia court, and recently fired his agent. —Matt Gelb, New York Times, 15 Apr. 2026

But even with that in mind, what happened to Garrett Crochet on Monday night was unthinkable. —Mac Cerullo, Boston Herald, 14 Apr. 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