Real Dictionary

differential in American English
of, showing, or depending on a difference or differences
adjective: of or pertaining to difference or diversity
noun: a difference or the amount of difference, as in rate, cost, quantity, degree, or quality, between things that are comparable

differential in Automotive Engineering
noun: A differential is a system of gears in a vehicle which allows two shafts to rotate at different speeds.

differential in British English
adjective: of, relating to, or using a difference
noun: a factor that differentiates between two comparable things

differential in Mechanical Engineering 1
adjective: Differential control is where the strength of the output is adjusted according to the rate of approach to the setpoint.

differential in Mechanical Engineering 2
noun: A differential is a type of gear train (= a series of gears on a frame) that allows two shafts to rotate at different speeds while being driven by a third shaft.