Synonyms of improbable

improbable

adjective

(ˌ)im-ˈprä-bə-bəl 

as in unlikely

not likely to be true or to occur

it seems improbable that the two writers never met since they traveled in the same social circles

Synonyms & Similar Words

• unlikely
• doubtful
• questionable
• dubious
• odd
• impossible
• far-fetched
• flimsy
• bizarre
• implausible
• incredible
• inconceivable
• unapt
• unbelievable
• fantastical
• unthinkable
• unimaginable
• ridiculous
• absurd
• fantastic
• outlandish
• foolish
• nonsensical
• preposterous
• unreal
• insane
• crazy
• wild
• remote
• slight
• outside

Antonyms & Near Antonyms

• probable
• likely
• plausible
• possible
• conceivable
• potential
• credible
• earthly
• believable
• imaginable
• liable

Example Sentences

Recent Examples of improbable

In an improbable turn of events on the back nine on Sunday, JJ Spaun conquered Oakmont to win the U.S. Open by two shots over Robert MacIntyre. —Troy Finnegan‎, MSNBC Newsweek, 16 June 2025

Chelmsford’s improbable run yielded wins over No. 19 Shrewsbury (1-0), No. 3 Bishop Feehan (12-3), No. 11 Wellesley (1-0) and No. 2 Saint John’s (5-3). —Jason Cooke, Boston Herald, 14 June 2025

Alcaraz, 22, made an improbable comeback to beat Jannik Sinner 4-6, 6-7 (4-7), 6-4, 7-6 (7-3), 7-6 (10-2). —Nicole Fallert, USA Today, 10 June 2025

While winning even one of these games was a highly improbable task for the Pacers, winning all four was extremely unlikely. —Rohan Nadkarni, NBC news, 8 June 2025