dynamic braking

noun Railroads.
  1. a braking system used on electric and diesel-electric locomotives in which the leads of the electric motors can be reversed so that the motors act as generators, offering resistance to the rotating wheel axles and dissipating kinetic energy, thereby retarding the locomotive.

Origin of dynamic braking

First recorded in 1925–30
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018