The Collaborative International Dictionary of English v.0.48:

airbrake \airbrake\ n.
   1. 1 a small parachute or articulated flap to reduce the
      speed of an aircraft.

   Syn: dive brake
        [WordNet 1.5]

   2. a vehicular brake that operates by compressed air;
      especially for heavy vehicles. Same as air brake.

   Syn: air brake
        [WordNet 1.5] n.

   1. an atomizer to spray by means of compressed air.
      [WordNet 1.5] airbrush

WordNet (r) 3.0 (2006):

airbrake
    n 1: a small parachute or articulated flap to reduce the speed
         of an aircraft [syn: airbrake, dive brake]
    2: a vehicular brake that operates by compressed air; especially
       for heavy vehicles