I understand it as a mathematical description of a process which degenerates over time to offer a large number of unpredictable and potentially conflicting outcomes  i.e. 'chaos'.

Tiny differences in a chaotic system at some time will become very large differences at a later time. This makes it unpredictable, because you can never measure/calculate precisely enough to know what'll happen far into the future. So even though the system is deterministic, you cannot determine it's evolution, it might as well be probablistic.

Sensitivity to initial conditions