backfire

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. An explosion of prematurely ignited fuel or of unburned exhaust gases in an internal-combustion engine.
2. n. The backward escape of gases or cartridge fragments when a gun is fired.
3. n. A fire started in the path of an oncoming fire in order to deprive it of fuel and thereby control or extinguish it.
4. v. To explode in the manner of or make the sound of a backfire.
5. v. To start or use a backfire in extinguishing or controlling a forest fire.
6. v. To produce an unexpected, undesired result.

Century Dictionary and Cyclopedia

1. To stop an advancing fire by setting in front of it, or around threatened buildings, woods, etc., another fire, which is then beaten out, thus producing a protective burnt area.
2. To light before the proper time: said specifically of a gas-engine when the charge explodes before the admission-valve closes, thus making an explosion in the admission-passage, or before the working-piston reaches its dead-center, which it must do before beginning its working stroke. See back-firing.
3. n. A fire started purposely some distance ahead of a fire which is to be fought. The back-fire is often so set as to burn against the wind, so that when the two fires meet, both must go out for lack of fuel. Also called counter-fire.

Wiktionary

1. v. to fire in the opposite direction, for example due to an obstruction in the barrel.
2. v. To fail in a manner that brings down further misfortune.
3. n. firefighting alternative spelling of back fire.

GNU Webster's 1913

1. A fire started ahead of a forest or prairie fire to burn only against the wind, so that when the two fires meet both must go out for lack of fuel.
2. A premature explosion in the cylinder of a gas or oil engine during the exhaust or the compression stroke, tending to drive the piston in a direction reverse to that in which it should travel; also called a knock or ping.
3. an explosion in the exhaust passages of an internal combustion engine.
4. v. (Engin.) To have or experience a back fire or back fires; -- said of an internal-combustion engine.
5. v. Of a Bunsen or similar air-fed burner, to light so that the flame proceeds from the internal gas jet instead of from the external jet of mixed gas and air.

WordNet 3.0

1. n. the backward escape of gases and unburned gunpowder after a gun is fired
2. v. emit a loud noise as a result of undergoing a backfire
3. v. come back to the originator of an action with an undesired effect
4. v. set a controlled fire to halt an advancing forest to prairie fire
5. n. a fire that is set intentionally in order to slow an approaching forest fire or grassfire by clearing a burned area in its path
6. n. a loud noise made by the explosion of fuel in the manifold or exhaust of an internal combustion engine
7. n. a miscalculation that recoils on its maker