101 entries under dubious topic. ×

6
unconvincing(adjective, weak, great, flat, poor)
5
crooked(adjective, false, corrupt, dishonest, immoral)
5
inconceivable(adjective, extraordinary, amazing, doubtful)
5
open to question(expression, adjective, idiom, uncertain, doubtful)
5
opprobrious(adjective, dishonorable, disreputable, infamous)
4
absurd(adjective, doubtful, unbelievable, implausible)
4
chancy(adjective, clear, certain, uncertain, doubtful)
4
misleading(adjective, uncertain, doubtful, faint, vague)
4
not kosher(expression, suspect, shady)
4
obnoxious
4
ridiculous(adjective, doubtful, absurd, suspicious)
4
strange(adjective, unusual, doubtful, unexpected)
4
thin(adjective, weak, great, extraordinary, amazing)
4
undetermined(adjective, uncertain, doubtful, vague, hesitant)
4
unsound(adjective, uncertain, unsettled, unpredictable)
4
unstable(adjective, open, obscure, uncertain, unsettled)
3
contentious(adjective, doubtful, provocative, debatable)
3
cryptic(adjective, uncertain, doubtful, vague)
3
dodgy(adjective, corrupt, dishonest, suspect)
3
enigmatic(adjective, uncertain, doubtful, vague)
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APASmart Define. (2015). questionable thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/questionable/thesaurus/synonyms
ChicagoSmart Define. 2015. "questionable thesaurus" https://smartdefine.org/questionable/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, questionable thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/questionable/thesaurus/synonyms>.
MLASmart Define. "questionable thesaurus" 13 April 2015. Web. 23 September 2026. <https://smartdefine.org/questionable/thesaurus/synonyms>