spontaneous combustion

American  

noun

1. the ignition of a substance or body from the rapid oxidation of its own constituents without heat from any external source.

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spontaneous combustion British  

noun

1. the ignition of a substance or body as a result of internal oxidation processes, without the application of an external source of heat, occurring in finely powdered ores, coal, straw, etc

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spontaneous combustion Scientific  

1. The bursting into flame of a mass of material as a result of chemical reactions within the substance, without the addition of heat from an external source. Oily rags and damp hay, for example, are subject to spontaneous combustion.

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spontaneous combustion Cultural  

1. A process by which a collection of materials (such as oily rags) catches fire without the application of heat from outside. The oxidation of substances in the materials starts the fire.

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Etymology

Origin of spontaneous combustion

First recorded in 1800–10

Example Sentences

See Examples For:

spontaneous combustion

They were also located in a layer that lacked guano deposits, ruling out spontaneous combustion as an explanation.

From Science Daily ● Jun. 24, 2026

"So it started with that flame. It was like spontaneous combustion."

From BBC ● Mar. 17, 2026

It is not a party, it is not a feast, it is not even an orgy; it is simply the spontaneous combustion of a bunch of people having a good time.

From Scientific American ● Mar. 31, 2022

But when the strings whirl into a vortex on the hard-charging “Vanishing,” it feels like spontaneous combustion rather than deliberate consideration.

From Washington Post ● Oct. 21, 2021

I thought of theory number five: spontaneous combustion.

From "The London Eye Mystery" by Siobhan Dowd