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

Democrats were right to insist that those concerns be addressed, and over the course of these negotiations, Republicans and the White House acepted ethics provisions that would have been unthinkable only months ago. — Anthony Scaramucci, Fortune, 1 Aug. 2026

Universal Creative, the division of the company responsible for theme park experiences, and especially the Universal Studios Hollywood team led by Jon Corfino, have accomplished what, just 10 years ago, would have been unthinkable. — Todd Martens, Los Angeles Times, 28 July 2026

Recently, Rodríguez was photographed in a once-unthinkable meeting with uniformed IDF brass overseeing Israeli rescue efforts in the wake of two powerful earthquakes that have devastated Venezuela’s coastal region. — Larry Luxner, Sun Sentinel, 20 July 2026

Reaching mainstream heights was once unthinkable for this radical, uncompromising act, but Paul sensed new horizons in the recording studio. — Steve Appleford, SPIN, 20 July 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