Synonyms of inconceivable

inconceivable

adjective

ˌin-kən-ˈsē-və-bəl 

as in incredible

too extraordinary or improbable to believe

the formerly inconceivable idea that humans could land on the moon

Synonyms & Similar Words

• incredible
• incredulous
• unlikely
• impossible
• unthinkable
• unimaginable
• unbelievable
• implausible
• absurd
• ridiculous
• unreasonable
• doubtful
• unconceivable
• questionable
• unconvincing
• silly
• full of it
• fantastic
• dubious
• uncompelling
• debatable
• suspect
• hopeless
• suspicious
• disputable
• fishy
• shaky
• ludicrous
• far-fetched
• flimsy
• untenable
• comical
• laughable
• preposterous
• outlandish
• farcical
• indefensible
• dubitable
• insupportable
• doubtable
• dodgy
• risible

Antonyms & Near Antonyms

• conceivable
• plausible
• possible
• imaginable
• thinkable
• credible
• convincing
• probable
• believable
• creditable
• likely
• reasonable
• supposable
• cogitable
• certain
• indisputable
• undeniable
• unquestionable
• sure
• incontestable
• indubitable
• undoubted
• questionless

Example Sentences

Recent Examples of inconceivable

This analogy is strangely anticlimactic and almost consoling, but a pedestrian ending comes with the territory in a scrupulously realistic book about the inconceivable. — Gideon Lewis-Kraus, New Yorker, 25 July 2026

The major innovation of pocket books became the big selling point of Casa Editorial Maucci, which saw its products sell at an inconceivable rate, spreading like wildfire. — Literary Hub, 22 July 2026

Conspiracy theorists have proposed many different (though mostly superstitious and inconceivable) reasons why disappearances and disasters occur in the Bermuda Triangle. — Andrea Romano, Travel + Leisure, 15 July 2026

And the power play was 17th in the NHL, which seems inconceivable for a team with as much offensive firepower as Tampa Bay. — Scott Turick, The Orlando Sentinel, 11 July 2026