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

Nelson’s uncle, Dave Christian, led the famed 1980 team in assists on the way to the improbable semifinal victory over the Soviet Union and gold medal win over Finland in Lake Placid, New York. —Dave Campbell, Chicago Tribune, 6 Feb. 2026

Yet amid the pressure, Maye’s poise and work ethic stand out as the foundation of this improbable journey. —Nathan Canilao, Mercury News, 5 Feb. 2026

These improbable captors are an average, often unreliable bunch, at least at first. —Bilge Ebiri, Vulture, 5 Feb. 2026

Cool, clear mornings give way to afternoons shaped by the low winter arc of the sun, painting the mountains in long shadows and the sky in improbable color. —Josh Jackson, Los Angeles Times, 5 Feb. 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