jake brakes
n.pl.— «If approved, the ordinance would prohibit within the city limits the use of hydraulically operated devices that convert a power-producing diesel or gas engine into a a powerabsorbing retarding mechanism with a correspondingly increased amount of noise emission. The use of such braking systems, often referred to as “jake brakes,” would be permitted in emergency situations or if the service brakes failed.» —“Hitting the brakes: Council to consider ordinance halting use of ‘jake brakes’” by Drew Terry Northwest Arkansas Times (Fayetteville) Apr. 5, 2005. (source: Double-Tongued Dictionary)