improbable

1 of 2

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

improbability

2 of 2

noun

im·​probability (¦)im 

əm+

1

: the quality or state of being improbable

questioned the improbability of a nuclear accident

2

: something improbable

Synonyms of improbable

Adjective

• unlikely

Examples of improbable in a Sentence

Adjective

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

Adjective

This one opens out to accommodate an improbable amount of worldly possessions— including a large laptop—without looking remotely utilitarian. — Elly Leavitt, Vogue, 22 Oct. 2026

That sounds deeply improbable, and seems like a potential issue for Butcherbird, Ultron, and any other synthetic life that never touched the stone. — Tasha Robinson, Vulture, 21 Oct. 2026

Stage a rally to give your fans hope of an improbable comeback … and then literally fumble the game away. — Ken Sugiura, AJC.com, 19 Oct. 2026

Chicago embarrassed Philadelphia, while the Eagles squandered a late lead against the Rams before suffering an improbable loss to the Jaguars in London. — Outkick, FOXNews.com, 18 Oct. 2026

Word History

Etymology

Adjective

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

First Known Use

Adjective

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