Synonyms of unthinkable

unthinkable

adjective

ˌən-ˈthiŋ-kə-bəl 

as in incredible

too extraordinary or improbable to believe

to most people it seemed unthinkable that such a gentle man could be guilty of such awful crimes

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

Example Sentences

Recent Examples of unthinkable

The idea that casual audiences on TV — people who weren’t gamers willing to grind to 100 percent completion to unlock an esoteric, secret two-minute cutscene ending — was almost unthinkable. — Brian Welk, IndieWire, 19 Aug. 2026

Panettiere tenderly conveys the turmoil of being a kid who’s just trying to keep it together in the face of unthinkable circumstances. — Patrick Ryan, USA Today, 18 Aug. 2026

The United States’ drop in credibility has also emboldened many American adversaries to push ahead with initiatives that would have been unthinkable 10 years ago, the closure of the Strait of Hormuz being the prime example. — Letters To The Editor, Washington Post, 18 Aug. 2026

Los Angeles Times via Getty Images For two consecutive years, the Buss family agreed to something that once seemed unthinkable. — Mark Medina, Forbes.com, 17 Aug. 2026