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

Down 3-1 after dropping the first three games, little has gone right for the Penguins against their most bitter rival, and advancing will require an improbable and historic comeback. —Josh Yohe, New York Times, 27 Apr. 2026

The purest example are the rooftop concerts, a rather improbable attempt to bring a little bit of Beatles-style magic to Chicago’s Clark Street, where The Weiner’s Circle is parked. —Jimmy Jellinek, SPIN, 27 Apr. 2026

Instead, the Broncos were left with their noses against the windowpane, two wins shy of the most improbable season in franchise history. —Troy Renck, Denver Post, 25 Apr. 2026

Vrabel, the 2025 NFL coach of the year, led New England to an improbable Super Bowl run in his first year at the helm, taking over the franchise after three straight losing seasons and consecutive 4-13 campaigns. —Valeriya Antonshchuk, NBC news, 23 Apr. 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