It was next to unthinkable that the boy would steal.
Source: tatoeba (46419)
Unthinkable
/ʌnˈθɪŋkəbəl/
Synonyms for "unthinkable" (91 found)
Ranked by relevance and common usage.
Closest matches (19)
a bit thicka bit thinabsurdbarredbeyond beliefclosed-outcontrary to reasondoubtabledoubtfuldubiousdubitableexceptionalexcludedextraordinaryhard of beliefhard to believehopeless
Strong matches (27)
illogicalimplausibleimpossibleimprobableincomprehensibleinconceivableincrediblelaughablelogically impossibleludicrousmind-blowingmind-bogglingnot deserving beliefnot possiblenot to be believedopen to doubtopen to suspicionout of the questionoutrageousoxymoronic
Show 1 more word
Adjective(6 words)
Related words (45)
passing beliefphenomenalpreposterousproblematicproblematicalprohibitedquestionquestionablerareridiculousruled-outself-contradictorysingularstaggering beliefsuspectsuspicioustallthickthinunacceptable
Show 15 more words
Adjective(10 words)
red lineremotereprehensibletaboounfathomableunimaginableunimaginablenessunlikelyunspeakablezero probability
Choosing the right synonym
- Closest matches in this entry: a bit thick, a bit thin, absurd, barred, beyond belief.
- Sentence evidence is available for unthinkable, so synonym choice can be checked against real usage rather than a flat word list.
- Ranking signals come from moby, opengloss, derived_reverse.
Synonym selection checklist
- Match the part of speech before comparing meanings.
- Check whether the synonym changes intensity, formality, or emotional tone.
- Read the replacement inside the full sentence, not just beside "unthinkable".
- Prefer the clearest word over the most unusual word when writing for speed or comprehension.
When not to replace "unthinkable"
Keep "unthinkable" when the sentence already sounds natural, when a synonym would add unintended emphasis, or when readers need the most familiar wording. A synonym should clarify or sharpen the message, not simply make the sentence look more varied.
If two options seem close, choose the one that best matches the audience and purpose of the sentence.
Replacement workflow
1. Preserve meaning
Choose a synonym only if it keeps the core idea of "unthinkable" intact in the sentence you are editing.
2. Tune tone
Check whether the replacement sounds more formal, casual, emotional, technical, or forceful than the original word.
3. Re-read context
Read the full sentence after the swap. Keep the synonym only when the sentence becomes clearer or more precise.
Review note: Synonym lists are ranked with lexical data and reviewed for practical writing value. Use the comparison notes, sentence evidence, and source labels together; a high-ranking synonym can still be wrong when the audience, register, or grammar changes.
Final fit check
After choosing a replacement for "unthinkable", read the sentence once for meaning and once for rhythm. The best synonym should feel natural in the full sentence, not only accurate in a word list.
If the synonym makes the sentence slower, vaguer, or more dramatic than intended, keep "unthinkable" or choose a simpler alternative from the closest-match group.
Related word relations
OpenGloss and ConceptNet supply richer edges like generalizations, collocations, and derivations.
More general
6 entriesMore specific
14 entriescatastrophic eventegregious misconductethical breachheinous offenseimpossibilityincomprehensible ideainconceivabilitylow probabilitypolicy breachrare eventremote possibilityreprehensible actunimaginable eventunimaginableness
Collocations
10 entriesthe unthinkableunthinkable actunthinkable barrierunthinkable consequencesunthinkable costunthinkable eventunthinkable propositionunthinkable scaleunthinkable scenariounthinkable threshold
Inflections
3 entriesDerivations
3 entriesAntonyms
1 entriessimilar
6 entriesSample sentences
21 total sentences available.
It is practically unthinkable that a scientist of his stature would have made such an elementary mistake.
Source: tatoeba (304891)
Essentially it's a one-to-one match, but the content of that match is a level so high as to be unthinkable to an ordinary person.
Source: tatoeba (328256)
Productive thinking and creativity are unthinkable without imagination.
Source: tatoeba (1228280)
Showing 4 of 21 available sentences.
Common questions
What are the closest synonyms for "unthinkable"?
Closest matches include a bit thick, a bit thin, absurd, barred, beyond belief.
How should I check whether a synonym fits "unthinkable"?
Compare the replacement against real sentence context. This entry includes sample sentences so you can check tone, grammar, and meaning before swapping words.