improbable

adjective

im·​prob·​a·​ble (ˌ)im-ˈprä-bə-bəl 

-ˈpräb-bəl

: unlikely to be true or to occur

also : unlikely but real or true

improbability

(ˌ)im-ˌprä-bə-ˈbi-lə-tē 

noun

improbably

(ˌ)im-ˈprä-bə-blē 

-ˈpräb-blē

adverb

Synonyms

• doubtful
• dubious
• far-fetched
• flimsy
• questionable
• unapt
• unlikely

Examples of improbable in a Sentence

The team made an improbable comeback.

it seems improbable that the two writers never met since they traveled in the same social circles

Recent Examples on the Web

The surprise run that the Atlanta Braves made to the 2021 World Series is one of the more improbable ones in recent memory. —Mohammed Soliman, MSNBC Newsweek, 28 Apr. 2025

Faced with a shot from behind a tree, don’t try to do the improbable. —Alec Lewis, New York Times, 25 Apr. 2025

There are also some caveats to note about the improbable lopsidedness exhibited by M31's satellites. —Keith Cooper, Space.com, 22 Apr. 2025

Although some relief could be found in 'deals' with certain countries, or as part of a market-calming exercise, a complete unwinding is deeply improbable. —Daniel De Visé, USA Today, 21 Apr. 2025

Word History

Etymology

Middle French or Latin; Middle French, from Latin improbabilis, from in- + probabilis probable

First Known Use

1598, in the meaning defined above

Rhymes for improbable

• probable

Kids Definition

improbable

adjective

im·​prob·​a·​ble (ˈ)im-ˈpräb(-ə)-bəl 

: not probable : unlikely to be true or to occur

improbability

(ˌ)im-ˌpräb-ə-ˈbil-ət-ē 

noun

improbably

(ˈ)im-ˈpräb(-ə)-blē 

adverb