Definition of undecidable
: not capable of being decided : not decidable
- … a huge popular audience, most of whom must have been baffled and exasperated by its elaborate and undecidable mystifications.
- —David Lodge
- … deconstruction, which teaches that literature is essentially "undecidable," beyond interpretation …
- —James Atlas
- To be complete such a system must be able to prove that any formula expressible in its language (a mathematical equation, for example, or a statement in symbolic logic) is either true or false; nothing can be undecidable.
- —George Johnson
