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
• 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

Portaluppi, whose architectural and interior designs rose to fame during the Art Deco and Rationalist periods, was known for his improbable structures and curious nooks and crannies filled with the sort of surprises that excite one’s inner child. — Sofia Celeste, Footwear News, 15 Sep. 2026

Coach Matt Potter led the Current on an improbable run to the 2022 NWSL championship. — Pj Green september 11, Kansas City Star, 11 Sep. 2026

However, an alliance of any kind between those parties is improbable and would be prone to instability. — ABC News, 7 Sep. 2026

Michigan quarterback Bryce Underwood found wide receiver JJ Buchanan with a 45-yard, last-second Hail Mary touchdown, giving the Wolverines an improbable and controversial 13-12 win over Western Michigan on Saturday night in Ann Arbor. — Leah Olajide, Freep.com, 6 Sep. 2026