from the GNU version of the Collaborative International Dictionary of English
- n. a kind of continuous brake operated by exhausting the air from some appliance under each car, and so causing the pressure of the atmosphere to apply the brakes.
from The Century Dictionary and Cyclopedia
- n. A form of continuous brake used on railroads, employing a steam-jet directly, and the pressure of the atmosphere indirectly, as a means of controlling the pressure.
Sorry, no etymologies found.