improbable

adjective

im·​prob·​a·​ble (ˌ)im-ˈprä-bə-bəl 

-ˈpräb-bəl

: unlikely to be true or to occur

an improbable story

also : unlikely but real or true

their improbable come-from-behind victory

improbability

(ˌ)im-ˌprä-bə-ˈbi-lə-tē 

noun

improbably

(ˌ)im-ˈprä-bə-blē 

-ˈpräb-blē

adverb

Synonyms of improbable

• 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

For one brief, improbable moment in the middle of the century, the arrangement very nearly worked. — Anthony Scaramucci, Fortune, 28 June 2026

The house also offers physical testament to the couple's improbable union. — Hamish Bowles, Vogue, 5 July 2026

Belgium also won in the round of 32 on Wednesday behind an improbable comeback over Senegal. — Andrew Greif, NBC news, 2 July 2026

To make the matchup even more improbable, the younger Muncy had missed more than a month with a left fifth metacarpal fracture, only being reactivated a few weeks before the Dodgers series. — Sean Campbell, Sacbee.com, 1 July 2026

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