air brake

American  

noun

1. a brake or system of brakes operated by compressed air.

2. Aeronautics. a device for reducing the air speed of an aircraft by increasing its drag.

3. a device for stopping the sails of a windmill by disrupting the flow of air around them.

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air brake British  

noun

1. a brake operated by compressed air, esp in heavy vehicles and trains

2. Also called: dive brake.  an articulated flap or small parachute for reducing the speed of an aircraft

3. a rotary fan or propeller connected to a shaft to reduce its speed

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Etymology

Origin of air brake

An Americanism dating back to 1870–75

Example Sentences

The air brake, invented by George Westinghouse in 1869, sent compressed air through a line to enable the train’s engineer to apply brakes from the locomotive.

From Textbooks • Dec. 14, 2022

Union Pacific failed to maintain the rail cars in accordance with federal regulations such as regularly performing single rail car air brake tests, according to the NTSB.

From Washington Times • Jan. 25, 2021

But trucks generally abide by a three-second rule, in part because their air brake systems take a little longer to engage.

From Slate • Jun. 8, 2015

But if the ball began spinning, the flaps would be flipped out by centrifugal force and act as an air brake, retarding the spin.

From Time Magazine Archive

It looked like the bird known to ornithology as the flyupithecrick, and had an air brake, patent coupler, buffer and platform.

From Remarks by Nye, Bill