5
improbable(adjective, extraordinary, fantastic, amazing, unbelievable)
5
mindless(adjective, careless, foolish, stupid, unreasonable)
5
pointless
5
self-contradictory(adjective, absurd, absurdity)
5
tall(adjective, hard, difficult, false, unreasonable)
5
thick(adjective, informal, extraordinary, amazing, ridiculous)
5
unimaginable(adjective, extraordinary, unreasonable, useless, absurd)
5
unlikely(adjective, obscure, strange, exceptional, crazy)
5
zany(adjective, weak, simple, knowledge, ability)
4
batty(adjective, strange, silly, foolish, stupid)
4
beyond belief(expression, adjective, idiom, extraordinary, amazing)
4
cockamamie(weak, simple, extraordinary, foolish, unreasonable)
4
curious(adjective, happy, perfect, strange, fantastic)
4
daffy(adjective, weak, simple, strange, foolish)
4
doubtful(adjective, extraordinary, fantastic, amazing, unbelievable)
4
eccentric(adjective, wild, strange, silly, foolish)
4
impracticable(adjective, wild, strange, silly, foolish)
4
nuts(adjective, wild, silly, foolish, stupid)
4
odd(adjective, wrong, false, unusual, wild)
4
outre(exaggeration, ridiculousness)
11 years ago|25k views|share |citing 
APASmart Define. (2015). preposterous thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/preposterous/thesaurus/synonyms
ChicagoSmart Define. 2015. "preposterous thesaurus" https://smartdefine.org/preposterous/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, preposterous thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/preposterous/thesaurus/synonyms>.
MLASmart Define. "preposterous thesaurus" 2 September 2015. Web. 21 September 2026. <https://smartdefine.org/preposterous/thesaurus/synonyms>