Something not definitely known or knowable; a doubtful point.

An instance of ambiguity (sense 1a) or uncertain meaning; a doubt; an uncertainty.

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…

A question, issue, etc., which is hard to decide or judge; a doubtful matter. Also: something which is hard to distinguish from something else; a…

The quality of being inconclusive; an instance of this, an inconclusive argument.

A disputable matter. Obsolete.

Something which cannot be defined.

Something (indefinite or left undefined) related in some way to two (definite or known) things, but distinct from both.

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

figurative. A question, a query, a doubt; (also) an enigma, an enigmatic person.

The condition of reaching no conclusion; an inconclusive result, an unwarranted conclusion.

The quality or fact of being disputable; a disputable matter.

a borderline case.

Something that cannot be decided; that which is undecidable.