nonlinear
(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.