6
unscrupulous(adjective, immoral)
6
unsteady(adjective, unreliable, insecure, treacherous, incalculable)
5
ambivalent(adjective, uncertain, doubtful, vague, hesitant)
5
conjectural(adjective, doubtful, vague, hesitant, changeable)
5
crooked(adjective, false, corrupt, dishonest, immoral)
5
deniable(adjective, uncertain)
5
devious(adjective, evil, false, corrupt, dishonest)
5
dishonorable(adjective, evil, corrupt, dishonest, crooked)
5
hazardous(adjective, shaky, unlikely, unpromising)
5
inconceivable(adjective, extraordinary, amazing, doubtful, dubious)
5
infamous(adjective, dishonest, shameful, crooked, dishonorable)
5
open to question(expression, adjective, idiom, uncertain, doubtful)
5
opprobrious(adjective, dubious, dishonorable, disreputable, infamous)
5
treacherous(adjective, corrupt, dishonest, deceitful, unpredictable)
5
trustless(adjective, uncertain, dishonest, doubtful, deceitful)
5
unpredictable(adjective, uncertain, doubtful, vague, hesitant)
4
absurd(adjective, doubtful, dubious, unbelievable, implausible)
4
alleged(supposed, unproven)
4
at issue(adjective, idiom, clear, certain)
4
chancy(adjective, clear, certain, uncertain, doubtful)
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APASmart Define. (2015). questionable thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/questionable/thesaurus/synonyms
ChicagoSmart Define. 2015. "questionable thesaurus" https://smartdefine.org/questionable/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, questionable thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/questionable/thesaurus/synonyms>.
MLASmart Define. "questionable thesaurus" 13 April 2015. Web. 20 September 2026. <https://smartdefine.org/questionable/thesaurus/synonyms>