Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
- a gear that at a certain speed automatically reduces an engine's power output without reducing its driving speed: used to lessen fuel consumption and engine wear
- Informal a state of intensified activity, productivity, etc.
Used by arrangement with John Wiley & Sons, Inc.
The 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 gearing mechanism of a motor vehicle engine that reduces the power output required to maintain driving speed in a specific range by lowering the gear ratio.
- Informal A state of heightened activity or concentration: shifted into overdrive toward the end of the semester.
- To drive (a vehicle) too far or too long.
- To push (oneself) too far, as in the performance of tasks.