backfire

American  

[bak-fahy^uhr] / ˈbækˌfaɪər /

verb (used without object)

backfired, backfiring

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.

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noun

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

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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

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

Appeared in the October 21, 2025, print edition as 'Beijing’s Minerals Brinkmanship May Backfire'.

From The Wall Street Journal • Oct. 20, 2025

"It is pretty hard to find too many people who think she did a great job there," said journalist Peter Burrows, who wrote "Backfire," a book about Fiorina's reign at HP.

From US News • Sep. 21, 2015

A Mandatory Ebola Quarantine Could Backfire, Experts Say A number of public health groups and experts are criticizing the governors’ decision.

From Forbes • Oct. 24, 2014

August 12 Two Moves by Manuel Backfire Playing David Wright and not pitching Francisco Rodriguez played a role in the Mets' 6-2 loss to Colorado on Wednesday night.

From New York Times • Aug. 12, 2010

Backfire bombers, reputed to be the Soviets' most capable air-to-surface missile carriers, were detected in larger numbers, and farther from their land bases, than ever before.

From Time Magazine Archive

Related Words

• fail
• flop