Meaning of linear equation

lin'ear equa'tion

Pronunciation: [key]
— Math. Math.
  1. a first-order equation involving two variables: its graph is a straight line in the Cartesian coordinate system.
  2. any equation such that the sum of two solutions is a solution, and a constant multiple of a solution is a solution. Cf.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.