(comparative more doubtable, superlative most doubtable)
- (uncommon) Capable of being doubted; doubtful; dubious; dubitable. .
Philosophers often use "doubtable" in its literal sense of "capable of being doubted." In other scholarly and literary contexts, the more accepted direct synonym of "doubtable" is "dubitable." In all other usage, "doubtful" and "dubious" are far more common synonyms.