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

• fantastic
• fantastical
• implausible
• inconceivable
• incredible
• incredulous
• unbelievable
• uncompelling
• unconceivable
• unconvincing
• unimaginable

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

Rita’s and Tyson’s journeys took them through unthinkable nightmares most people live very far from. —Kevin Fagan, TIME, 4 Feb. 2025

But that very scenario — a team on the brink through the stretch run — has morphed from unthinkable to plausible in four short months. —Jon Wilner, The Mercury News, 3 Feb. 2025

That list could grow this weekend if The Rise and Fall of a Midwest Princess, Chappell Roan’s spectacular pop debut, takes home the top prize — an unthinkable outcome 16 months ago, when the album was released to little fanfare in September 2023. —Jason Lipshutz, Billboard, 31 Jan. 2025

This has truly been the most devastating unthinkable for so many, and this is our chance to help. —Stephanie Giang-Paunon, Fox News, 19 Jan. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing unthinkable

• the unthinkable

Kids Definition

unthinkable

adjective

un·​think·​able ˌən-ˈthiŋ-kə-bəl 

ˈən-

: not to be thought of or considered as possible

unthinkable cruelty