Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
- a brake operated by the action of compressed air on a piston
- popularly speed brake
Used by arrangement with John Wiley & Sons, Inc.
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
- A brake, especially on a motor vehicle, that is operated by compressed air.
- A surface, such as an aileron, that can be projected into the airflow in order to decrease the air speed of an airplane by increasing drag; a spoiler.