What does nonlinear mean?
Nonlinear describes a relationship, process, or system that does not follow a straight-line or directly proportional pattern. In everyday language, it can refer to anything whose development is influenced by interacting factors, making outcomes less predictable than those in a simple linear process. The term is especially important in mathematics, physics, engineering, economics, and biology, where nonlinear systems may produce disproportionate changes, feedback effects, and sudden transitions. For example, a nonlinear model may show that increasing an input does not produce an equal increase in the output, or that a small change in one variable has a disproportionately large effect on another. The word is also used figuratively in phrases such as “nonlinear thinking,” meaning a process that moves between ideas or approaches rather than following one straight sequence.
adjectiveNot linear; involving or describing relationships, processes, or systems that do not follow a straight-line or proportional pattern.
- Describing something that does not follow a straight-line, constant-rate, or directly proportional relationship.
"The researchers developed a nonlinear model to account for the changing effects of temperature."
"The growth of the population is nonlinear, so small changes can produce disproportionately large effects."
"Nonlinear dynamics can make weather patterns especially difficult to predict."
Nonlinear thinking breaks away from the comforting idea that more input always produces proportionally more output.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does nonlinear come from?
The word combines the prefix non-, meaning “not,” with linear, which comes from Latin linearis, “of or relating to a line.” Linear itself is based on linea, “linen thread” or “line,” and ultimately on linum, meaning “flax.” The combination nonlinear became established in the 20th century, especially in mathematics and the natural sciences, to describe relationships that do not follow a straight-line or proportional form.
Related word forms
How nonlinear is actually used
Widely used in mathematics, science, engineering, economics, and everyday discussion. In general use, it can suggest that a situation is complicated or governed by interacting factors rather than a simple sequence.
Easily confused with nonlinear
A linear relationship changes in a directly proportional, straight-line way, whereas a nonlinear relationship does not.