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

Many Democratic leaders predict that the House majority is all but theirs, and that the Senate majority, almost unthinkable a year ago, is nearly in their grasp as well. — ABC News, 30 Sep. 2026

Micron is generating margins that would have been almost unthinkable in previous memory cycles, while the stock still trades at one of the lowest earnings multiples in the S & P 500 . — Isabella Gao, CNBC, 29 Sep. 2026

That would be impractical in Soho and unthinkable in Times Square. — Adriane Quinlan, Curbed, 29 Sep. 2026

Japan, a country constitutionally bound to pacifism since World War II, is investing in its defense and contributing to regional security in ways that were previously unthinkable. — David Sacks, Foreign Affairs, 28 Sep. 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