doubtable

Etymology
From, from , , equivalent to.

Adjective

 * 1)  Capable of being doubted; doubtful; dubious; dubitable. See usage notes below.
 * 2)  Fearsome; redoubtable.
 * 1)  Fearsome; redoubtable.

Usage notes
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. See also dubious § Usage notes.