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

• incredible
• incredulous
• unlikely
• impossible
• inconceivable
• unimaginable
• fantastical
• 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

Up the road inside the Lakers’ film room, that’d be unthinkable. —Dan Woike, New York Times, 1 Oct. 2025

Still, Punch's moving message about the true power of connection and understanding in the wake of unthinkable tragedy is one that is desperately needed these days. —Emlyn Travis, Entertainment Weekly, 30 Sep. 2025

Private equity and private credit, once unthinkable, have suddenly become both intriguing and contentious prospects for athletic departments. —Eben Novy-Williams, Sportico.com, 25 Sep. 2025

Tigers miss playoffs For most of the season, this was an unthinkable outcome in Detroit. —Christian Romo, Freep.com, 23 Sep. 2025

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