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

Before this day is done, we shall be faced with an unthinkable decision. — Jeff Spry, Space.com, 20 July 2026

This might have been an unthinkable approach to an event held in the States as recently as a couple of decades ago, before the globalization of pop got vast American audiences singing along with hits in languages other than English. — Judy Berman, Time, 19 July 2026

The lasting impact of the series would be unthinkable without the Barnabas character – the vampire was even slyly name-checked in the current hit Apple TV+ series Widow’s Bay. — Greg Evans, Deadline, 18 July 2026

This ongoing divide is a recipe for frustration at best and unthinkable defeat at worst. — Bill McKibben, New Yorker, 16 July 2026