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

• 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 worst moment came a few moments later, when Matt Leinart completed an improbable pass on fourth down. —The Athletic College Football Staff, New York Times, 11 July 2025

The latest improbable yet inescapable sequel series premieres 21 years after Dexter first emerged, and like most Floridians who just reached legal drinking age, there’s nothing sober about it. —Ben Travers, IndieWire, 10 July 2025

Whitaker, meanwhile, has a thankless role as an empath whose narrative function flips between making improbable, almost psychic pronouncements, and stating the painfully obvious. —Richard Edwards, Space.com, 7 July 2025

Indeed, Holmgren’s victory defines the word improbable. —Ivan Carter, San Diego Union-Tribune, 3 July 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