nonlinear

adjective5

1. •
   Of a set of points, not lying on a straight line.
2. •
   Erratic and unpredictable; tending to jump back and forth.
3. •
   Of a function, having a product of independent variables, or a variable with an exponent not equal to one.
4. •
   Of a system, whose output is not directly proportional to its input.
5. •
   Of a molecule, whose atoms do not lie in a straight line.