Unpredictable; impossible to know a priori.
Not sure whether it's going to end up one way or another.

In theoretical computer science (a branch of mathematics), nondeterminism is usually applied to discrete processes or algorithms, and it means, stepwise progression in a series of discrete steps, but with possibly several choices along the way.

Nondeterministic algorithms are convenient in the description of search algorithms; and play an important role in complexity theory.