1. to have an opposite and undesirable result from what was intended
2. to make a loud popping sound due to improper combustion in an engine

1. a loud popping sound from an engine due to improper combustion
2. a result that is opposite to what was intended

Examples

• His plan to embarrass his rival backfires when everyone laughs at him instead.
• The old truck backfires loudly as it starts up.
• Their attempt to save money backfires and costs them more.
• The car’s backfire startled the pedestrians.
• The marketing campaign backfires and damages the company’s reputation.
• We heard several backfires from the motorcycle.
• Her scheme to get attention backfires completely.