'nonlinear' definitions:

Definition of 'nonlinear'

(from WordNet)
adjective
Designating or involving an equation whose terms are not of the first degree [ant: additive, linear]

Definition of 'nonlinear'

From: GCIDE
  • nonlinear \nonlinear\ adj.
  • 1. (Math.) Not depictable graphically as a straight line; not changing by a constant amount for each unit of time, distance, or other independent variable. Opposite of linear. [WordNet 1.5 +PJC]
  • 2. (Math.) Containing variables of greater than the first degree; -- of an equation. Opposite of linear. [PJC]
  • 3. (Physics) Represented by equations containing variables of greater than the first degree; -- of physical processes or relationships. Opposite of linear. [PJC]