Of a matter, discussion, etc.: not finally settled or determined; that may be decided according to circumstances or at will; (hence) still admitting…

Doubtful; of uncertain existence, meaning, or issue.

About which one cannot be certain or assured; subject to doubt.

Doubtful; dubious; hazardous.

Of, relating to, or tending to lead to strife or disagreement; disputable. Cf. brigose, adj.

That may be doubted; doubtful, uncertain, questionable, dubitable.

Of things: Involved in doubt or uncertainty; uncertain, undecided; indistinct, ambiguous.

Of a thing, fact, etc.: open to question or dispute; doubtful, uncertain. Frequently in it is questionable whether (also if).

Debatable, disputed; used esp. of the ‘debatable ground’ on the Scottish border.

Open to dispute, disputable.

That may or should be inquired about or into; that admits of or calls for inquiry; open to inquiry. (Chiefly in legal use.) Also with into.

Open to dispute or question; disputable, questionable; productive of litigation or contention. Obsolete.

= doubtful, adj.

That may be disputed, questioned, or discussed; liable to be called in question, contested, or controverted; questionable.

Objectively doubtful; fraught with doubt or uncertainty; uncertain, undetermined; indistinct, ambiguous, vague.

Uncertain, doubtful. Obsolete.

Originally in Law, of a case, issue, etc.: proposed for discussion at a moot (moot, n.1 4). Later also gen.: open to argument, debatable…

Of the nature of a problem; = problematic, adj. 1.

Capable of being examined, debated, or discussed; open to discussion; = discussable, adj. 1.

Admitting of debate or controversy; subject to dispute; questionable.

Giving rise or likely to give rise to controversy or public disagreement; subject to (heated) discussion or debate; contentious, questionable…

That is the subject of disputation or dispute; controversial; controverted. Obsolete.

Of things. Controversial, contentious.

That has yet to be decided; still open to decision. Obsolete.

= controvertible, adj.

Capable of being controverted; contestable, disputable, questionable. Cf. incontrovertible, adj.

Giving rise to controversy; contentious; = controversial, adj. 1.

= controvertible, adj.

Of the nature of a problem; constituting or presenting a problem or difficulty; difficult to resolve; doubtful, uncertain, questionable.

= controversial, adj.

figurative and in extended use. Ambiguous, doubtful, questionable, spurious. In later use esp. of praise, a compliment, etc.: having an effect…

That is made the subject of dispute, debate, or contention; debated, contested.

Capable of being doubted; liable to doubt or question.

capable of being or liable to be challenged in a court of law.

Uncertain; precarious. Obsolete. rare.

Uncertain; undecided. Obsolete.

Tending to lead to strife or disagreement. Cf. brigous, adj.

That may be contested; disputable, debatable.

Of advantages, merits, etc.: Dubiously genuine, questionable.

= controversial, adj.

Capable of being contradicted.

Capable of being discussed; open to discussion.

Suspect, questionable. Also: unreliable, not working properly.