Nonlinearity is a term used in mathematics and other scientific disciplines to describe systems and processes that do not exhibit a linear relationship between cause and effect. Some synonyms for nonlinearity include complexity, unpredictability, nonlinearity, chaos, and turbulence. These terms describe systems that are highly sensitive to initial conditions, making them difficult to predict or control. Complexity refers to systems that are made up of many interconnected parts, making them difficult to understand and predict. Unpredictability refers to the difficulty in predicting how a system will behave over time. Nonlinearity describes the fact that seemingly small changes in input can have disproportionate effects on output. Chaos and turbulence suggest a complete breakdown of predictability and control.