1. A failure in a device attributable to burning, excessive heat, or friction.
2. Aerospace.
   1. The termination of rocket or jet-engine operation because of fuel exhaustion or shutoff.
   2. The point at which this termination occurs.
3. 1. Physical or emotional exhaustion, especially as a result of long-term stress or dissipation.
   2. One who is worn out physically or emotionally, as from long-term stress.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.