Back Fire

Part of speech: noun (n.)

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, an explosion in the exhaust passages of such ah engine.

Part of speech: verb (v.)

1. To have or experience a back fire or back fires; -- said of an internal-combustion engine.

2. 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. -- Back"-fir`ing, n.