Backfire (verb)

1. To produce the opposite of the desired result.
2. To cause (an engine or vehicle) to make a loud noise caused by the sudden burning of unburned fuel in the exhaust system.

Origin:

From back + fire.

Examples:

1. The plan backfired and they lost more business than they gained.
2. His attempt to scare her backfired and she became more determined.
3. The car's engine backfired, making a loud noise.
4. The company's attempts to limit competition backfired and it ended up facing even more competition.
5. Backfiring is the sound made when unburned fuel is ignited in the exhaust system of an internal combustion engine.