- [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
- [verb] have an unexpected and undesired effect; "Your comments may backfire and cause you a lot of trouble"
- [verb] emit a loud noise as a result of undergoing a backfire; "My old car backfires all the time"
- [verb] set a controlled fire to halt an advancing forest to prairie fire