backfire

from The American Heritage® Dictionary of the English Language, 5th Edition.

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

from The Century Dictionary.

• 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.
• 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.
• noun A fire started purposely some distance ahead of a fire which is to be fought.

from the GNU version of the Collaborative International Dictionary of English.

• 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.
• 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.
• an explosion in the exhaust passages of an internal combustion engine.
• intransitive verb (Engin.) To have or experience a back fire or back fires; -- said of an internal-combustion engine.
• intransitive verb 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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb to fire in the opposite direction, for example due to an obstruction in the barrel.
• verb To fail in a manner that brings down further misfortune.
• noun firefighting Alternative spelling of back fire.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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