air brake

a brake or system of brakes operated by compressed air.

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

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

Origin of air brake

An Americanism dating back to 1870–75

Callahan was seventeen, with hair like a sunset, and a mind quick as an air-brake.

The Nerve of Foley |Frank H. Spearman
A hundred yards from the struggling mass of frightened cattle, Brockway saw that the air-brake was not holding.

A Romance in Transit |Francis Lynde
He checked—and with a scream from the flanges the special, shaking in the clutches of the air-brake, swung the curve.

Held for Orders |Frank H. Spearman
Ever notice how human an engine sounds when it stops after a long run and the air-brake apparatus begins to pant?

Homeburg Memories |George Helgesen Fitch

His experiments cost thousands of dollars, but they established the practicability of the air-brake.

The Scrap Book. Volume 1, No. 2 |Various

air brake

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

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

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