verb (used without object), back·fired, back·fir·ing.
- (of an internal-combustion engine) to have a loud, premature explosion in the intake manifold.
- to bring a result opposite to that which was planned or expected: The plot backfired.
- to start a fire deliberately in order to check a forest or prairie fire by creating a barren area in advance of it.
- (in an internal-combustion engine) premature ignition of fuel in the intake manifold.
- an explosion coming out of the breech of a firearm.
- a fire started intentionally to check the advance of a forest or prairie fire.
- (of an internal-combustion engine) to emit a loud noise as a result of an explosion in the inlet manifold or exhaust system
- (of an endeavour, plan, etc) to have an unwanted effect on its perpetratorhis plans backfired on him
- to start a controlled fire in order to halt an advancing forest or prairie fire by creating a barren area
- (in an internal-combustion engine)
- an explosion of unburnt gases in the exhaust system
- a premature explosion in a cylinder or inlet manifold
- a controlled fire started to create a barren area that will halt an advancing forest or prairie fire
1839, American English, originally “a fire deliberately lit ahead of an advancing prairie fire to deprive it of fuel,” from back (adj.) + fire (n.). As a verb in this sense, recorded from 1886. The meaning “premature ignition in an internal-combustion engine” is first recorded 1897. Of schemes, plans, etc., “to affect the initiator rather than the intended object” it is attested from 1912, a figurative use from the accidental back-firing of firearms.