Pronunciation: (dif"u-ren'shul),[key] —adj. 1. of or pertaining to difference or diversity.
2. constituting a difference; distinguishing; distinctive: a differential feature. 3. exhibiting or depending upon a difference or distinction.
4. Physics,Mach.pertaining to or involving the difference of two or more motions, forces, etc.
5. Math.pertaining to or involving a derivative or derivatives.

—n. 1. a difference or the amount of difference, as in rate, cost, quantity, degree, or quality, between things that are comparable.
2. Also called differential gear.Mach.an epicyclic train of gears designed to permit two or more shafts to rotate at different speeds, as a set of gears in an automobile permitting the rear wheels to be driven at different speeds when the car is turning.
3. Math. a. a function of two variables that is obtained from a given function, y = f(x), and that expresses the approximate increment in the given function as the derivative of the function times the increment in the independent variable, written as dy = f'(x)dx. b. any generalization of this function to higher dimensions.
4. Com. a. the difference involved in a differential rate.
b. See differential rate. 5. Physics.the quantitative difference between two or more forces, motions, etc.: a pressure differential.