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

But their primitive way of living reveals itself to rather more devastating effect when their third child is born, and Inger commits an act of unthinkable desperation. — Guy Lodge, Variety, 16 Sep. 2026

Not long ago, the idea of an undersized forward prospect with 68 career NHL games and 27 career points receiving more than $50 million would have been unthinkable. — James Mirtle, New York Times, 15 Sep. 2026

These experiences complement our research on how policies once considered unthinkable can gain acceptance among the public and policymakers. — Karyn Sporer, The Conversation, 14 Sep. 2026

Those women were just called monsters, they were called evil, they were called unthinkable. — Jaha Nailah Avery, Vulture, 11 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