9
infeasible(adjective, wild, unreasonable, useless, absurd)
9
intolerable(adjective, pain, terrible, unacceptable, incredible)
8
illogical(adjective, wild, unreasonable, useless, absurd)
8
implausible(adjective, hard, great, difficult, extraordinary)
8
ludicrous(adjective, absurd, intolerable, ungovernable)
8
unachievable(adjective, impractical, pessimistic, desperate, unpromising)
8
unrealistic(adjective, false, wild, practical, absurd)
8
unreasonable(adjective, hard, difficult, unusual, stupid)
7
insupportable(adjective, pain, extreme, painful, insufferable)
7
irreparable(adjective, hopeless, unable)
6
cringeworthy
6
incurable
6
out of the question(expression, adjective, idiom, wild, stupid)
6
outlandish(adjective, hard, difficult, extraordinary, silly)
6
unrealizable(adjective, unreasonable, possible, inaccessible, unpractical)
6
unsufferable(adjective, pain, unbearable)
5
imaginary(adjective, perfect, ideal, number, lofty)
5
incomprehensible
5
irremediable(adjective, hopeless)
5
paradoxical(adjective, absurd)
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APASmart Define. (2016). impossible thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/impossible/thesaurus/synonyms
ChicagoSmart Define. 2016. "impossible thesaurus" https://smartdefine.org/impossible/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, impossible thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/impossible/thesaurus/synonyms>.
MLASmart Define. "impossible thesaurus" 9 March 2016. Web. 22 September 2026. <https://smartdefine.org/impossible/thesaurus/synonyms>