What it means

1. noun a miscalculation that recoils on its maker
2. 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
3. noun a loud noise made by the explosion of fuel in the manifold or exhaust of an internal combustion engine
4. noun the backward escape of gases and unburned gunpowder after a gun is fired
5. verb set a controlled fire to halt an advancing forest to prairie fire
6. verb emit a loud noise as a result of undergoing a backfire
   “My old car backfires all the time”
7. verb come back to the originator of an action with an undesired effect
   “Your comments may backfire and cause you a lot of trouble”