Source : Webster's Revised Unabridged Dictionary (1913)

Air brake \Air" brake`\ (Mach.)
   A railway brake operated by condensed air. --Knight.

Brake \Brake\ (br[=a]k), n. [OE. brake; cf. LG. brake an
   instrument for breaking flax, G. breche, fr. the root of E.
   break. See Break, v. t., and cf. {Breach}.]
   1. An instrument or machine to break or bruise the woody part
      of flax or hemp so that it may be separated from the
      fiber.

   2. An extended handle by means of which a number of men can
      unite in working a pump, as in a fire engine.

   3. A baker's kneading though. --Johnson.

   4. A sharp bit or snaffle.

            Pampered jades . . . which need nor break nor bit.
                                                  --Gascoigne.

   5. A frame for confining a refractory horse while the smith
      is shoeing him; also, an inclosure to restrain cattle,
      horses, etc.

            A horse . . . which Philip had bought . . . and
            because of his fierceness kept him within a brake of
            iron bars.                            --J. Brende.

   6. That part of a carriage, as of a movable battery, or
      engine, which enables it to turn.

   7. (Mil.) An ancient engine of war analogous to the crossbow
      and ballista.

   8. (Agric.) A large, heavy harrow for breaking clods after
      plowing; a drag.

   9. A piece of mechanism for retarding or stopping motion by
      friction, as of a carriage or railway car, by the pressure
      of rubbers against the wheels, or of clogs or ratchets
      against the track or roadway, or of a pivoted lever
      against a wheel or drum in a machine.

   10. (Engin.) An apparatus for testing the power of a steam
       engine, or other motor, by weighing the amount of
       friction that the motor will overcome; a friction brake.

   11. A cart or carriage without a body, used in breaking in
       horses.

   12. An ancient instrument of torture. --Holinshed.

   {Air brake}. See {Air brake}, in the Vocabulary.

   {Brake beam} or {Brake bar}, the beam that connects the brake
      blocks of opposite wheels.

   {Brake block}.
       (a) The part of a brake holding the brake shoe.
       (b) A brake shoe.

   {Brake shoe} or {Brake rubber}, the part of a brake against
      which the wheel rubs.

   {Brake wheel}, a wheel on the platform or top of a car by
      which brakes are operated.

   {Continuous brake} . See under {Continuous}.