undecidable adjective & noun. [ʌndɪ'sʌɪdǝb(ǝ)l] M17.
[from UN-¹ + DECIDABLE.]
A. adjective.
1. Unable to be decided. M17.

2. Math. & Logic. Of a proposition etc.: unable to be either proved or disproved (within a given formal system). M20.
b. noun. That which is undecidable. M20.

■ undecida'bility noun M20.

[TahlilGaran] English Dictionary ▲