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

Burrow found Tee Higgins for an improbable, one-handed touchdown 50 seconds later, but Buffalo still scored one of the more dramatic wins of the season. —Chris Bumbaca, USA Today, 8 Dec. 2025

With the excitement of Boise State football’s improbable run to host the Mountain West championship game, fans could be forgiven for not paying a ton of attention to the program just across the parking lot that’s heading into the thick of its season. —Shaun Goodwin, Idaho Statesman, 5 Dec. 2025

In a recent podcast appearance with Joe Rogan, the Nvidia CEO traced that improbable starting point back to his parents, who had sent him and his brother to the United States in the mid-1970s with almost nothing. —Eva Roytburg, Fortune, 5 Dec. 2025

This year, in July, many of the players and staff from that championship squad returned to Kansas City to celebrate the 25th anniversary of a most improbable run. —Daniel Sperry, Kansas City Star, 4 Dec. 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