backfire

American  

[bak-fahy^uhr] / ˈbækˌfaɪər /

verb (used without object)

• backfires,
  present (3rd person singular)
• backfired,
  past participle,  past
• backfiring
  present participle

1. (of an internal-combustion engine) to have a loud, premature explosion in the intake manifold.

2. to bring a result opposite to that which was planned or expected.

   The plot backfired.

   Synonyms:

   bomb, flop, boomerang, miscarry

3. to start a fire deliberately in order to check a forest or prairie fire by creating a barren area in advance of it.

---

noun

• backfires
  plural

1. (in an internal-combustion engine) premature ignition of fuel in the intake manifold.

2. an explosion coming out of the breech of a firearm.

3. a fire started intentionally to check the advance of a forest or prairie fire.

backfire British  

/ ˌbækˈfaɪə /

verb

1. (of an internal-combustion engine) to emit a loud noise as a result of an explosion in the inlet manifold or exhaust system

2. (of an endeavour, plan, etc) to have an unwanted effect on its perpetrator

   his plans backfired on him

3. to start a controlled fire in order to halt an advancing forest or prairie fire by creating a barren area

---

noun

1. 1. an explosion of unburnt gases in the exhaust system

   2. a premature explosion in a cylinder or inlet manifold

2. a controlled fire started to create a barren area that will halt an advancing forest or prairie fire

Other Word Forms

Inflected Forms

Nouns

• backfires
  plural

Participles

• backfiring
  present
• backfired
  past

Conjugated Forms

Present

• backfire
  simple
• backfires
  simple
• have backfired
  perfect
• has backfired
  perfect
• am backfiring
  progressive
• are backfiring
  progressive
• is backfiring
  progressive
• have been backfiring
  perfect progressive
• has been backfiring
  perfect progressive

Past

• backfired
  simple
• had backfired
  perfect
• was backfiring
  progressive
• were backfiring
  progressive
• had been backfiring
  perfect progressive

Future

• will backfire
  simple
• will have backfired
  perfect
• will be backfiring
  progressive
• will have been backfiring
  perfect progressive

Etymology

Origin of backfire

An Americanism dating back to 1775–85; back ² + fire

Explanation

Use the word backfire when you talk about the sound a car makes when a small explosion in its exhaust system pops — sometimes as loudly as a gunshot. Hearing a car's backfire can make you jump, because it makes a sharp, shot-like sound. A backfire is usually caused by unburned fuel, and it can be accompanied by a burst of flame and a brief loss of power in the vehicle, as well as a fairly loud noise. The word comes from an American English term that originally referred to a fire deliberately set to slow the progress of a prairie or forest fire.

Example Sentences

See Examples For:

backfire backfires backfired backfiring

"It seems to me that this has the potential to backfire spectacularly," she said.

From Barron's ● Sep. 10, 2026

But there’s no way this could possibly backfire, right?

From Salon ● Aug. 17, 2026

Britney Nguyen looked into a forward-looking factor helping drive the resurgence in chip makers, and how it could backfire.

From MarketWatch ● Aug. 14, 2026

But marketing buzz can fade, and poor perceptions regarding quality and sustainability can backfire on a company.

From The Wall Street Journal ● Aug. 7, 2026

Then he would sit and brood for hours while Mary frantically built up a backfire of gaiety.

From "Cannery Row" by John Steinbeck

The company has long relied on this high-yielding equity as its primary engine to bankroll Bitcoin acquisitions—a strategy that backfires when the shares lose ground.

From Barron's ● Jun. 26, 2026

All of the above comes with a caveat: Unbridled choice often backfires.

From The Wall Street Journal ● Jun. 14, 2026

"Discord could lose users if its implementation of age verification backfires, but it could equally attract more new users who will be drawn to its new standards for online safety by design," he said.

From BBC ● Feb. 9, 2026

Officers potentially wasting thousands of hours in pursuit of car backfires and construction noise mislabeled as gunfire has not deterred the New York Police Department from continuing to use it.

From Salon ● Feb. 8, 2026

The car behind me at the drive-thru backfires, and I rush inside.

From "Dumplin'" by Julie Murphy

The last time they tried, it backfired spectacularly.

From Los Angeles Times ● Aug. 21, 2026

But a police crackdown on crowds marching towards parliament on July 20 backfired, galvanising support for the movement and transforming anger over exam leaks into a broader expression of youth frustration.

From Barron's ● Jul. 29, 2026

The chain has experienced other problems as well, including remodels that backfired, agitation among activist investors and same-store sales that have wobbled over Masino’s three-year tenure.

From MarketWatch ● Jul. 28, 2026

On one occasion, turning to the bot for help navigating an in-person chat with friends actually backfired on her.

From The Wall Street Journal ● Jul. 26, 2026

A hands-off policy had backfired, the insurgents had gathered strength.

From "The Milagro Beanfield War" by John Nichols

But in Brazil’s conservative heartland, that strategy is backfiring.

From The Wall Street Journal ● Aug. 29, 2026

But Frazer Rhodes, who worked in government across a decade to help build the technology and devise high thresholds for the alerts, feels a review is now necessary to avoid future ones backfiring.

From BBC ● Aug. 29, 2026

Nestlé tweaked its portfolio, but investors say some acquisitions were a distraction, backfiring as the company expanded into non-core areas.

From Barron's ● Jun. 10, 2026

Sullivan warned that changes to VA policy that take decision-making out of veterans’ control is a risk that could seriously backfiring.

From Salon ● Mar. 14, 2026

Then a truck came toward us with its chains ratding and its engine backfiring.

From "The Stranger" by Albert Camus

Related Words

• fail
• flop