68 entries under doubtful topic. ×

2
debatable(adjective, uncertain, shaky, unsure)
2
equivocal(adjective, uncertain, unsure)
2
faint
2
iffy(adjective, uncertain, shaky, likely)
2
impracticable(adjective, wild, silly, unreasonable)
2
problematic(adjective, uncertain, unreasonable, shaky)
2
shady(uncertain, shaky, unsure, unlikely)
2
suspect(extraordinary, uncertain, unreasonable, dubious)
2
suspicious(uncertain, fantastic, unsure, unbelievable)
2
unapt(adjective, likely)
1
arguable(uncertain, unsure)
1
chancy(uncertain, shaky, unsure, unlikely)
1
diffident(uncertain, unsure)
1
disputable(uncertain, unsure)
1
fly-by-night(uncertain, unsure)
1
hesitant(uncertain, unsure)
1
hundred-to-one(adjective, likely, unlikely, implausible)
1
inconclusive(adjective, open, obscure, poor, thin)
1
indecisive(uncertain, unsure)
1
moot(uncertain, unsure)
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APASmart Define. (2015). improbable thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/improbable/thesaurus/synonyms
ChicagoSmart Define. 2015. "improbable thesaurus" https://smartdefine.org/improbable/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, improbable thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/improbable/thesaurus/synonyms>.
MLASmart Define. "improbable thesaurus" 14 April 2015. Web. 21 September 2026. <https://smartdefine.org/improbable/thesaurus/synonyms>