(Scientific computation) A property of a system whose output is not proportional to its input. For example, a tranSIstor has a region of input voltages for which its output voltage is found by multiplying the input voltage by the gain of the tranSIstor. OutSIde this region though, the tranSIstor behaves non-linearly, meaning that it does not obey this SImple equation. The behaviour of a system containing non-linear components is thus harder to model and to predict. [Jargon File]