unthinkable

1 of 2

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

unthinkability

2 of 2

noun

un·​think·​abil·​i·​ty ¦ənˌthiŋkə¦bilətē 

: the quality or state of being unthinkable

Synonyms of unthinkable

Adjective

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

Examples of unthinkable in a Sentence

Adjective

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

Recent Examples on the Web

Adjective

Westbrook walks away as the undisputed Triple-Double King with 209, blowing past Oscar Robertson's once-unthinkable record of 181. — Alejandro Avila Outkick, FOXNews.com, 12 Aug. 2026

An intimate and cinematic story, Under Salt Marsh takes audiences into the heart of a community bound by nature and fractured by an unthinkable crime. — Jesse Whittock, Deadline, 11 Aug. 2026

And historical records tell us that the latter remained unthinkable for Japan’s military leaders. — James M. Scott, Time, 10 Aug. 2026

More than a decade later, that once-unthinkable milestone has been surpassed again and again, with the most exclusive properties commanding prices that would have seemed almost fictional a generation ago. — Mark David, Robb Report, 7 Aug. 2026

Word History

First Known Use

Adjective

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