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

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

From BBC • Mar. 17, 2026

Each is internet famous, with Golden Boy's powers of spontaneous combustion and superstrength placing him on track to join The Seven right after he graduates.

From Salon • Sep. 29, 2023

But Vaillant also characterizes the wildfire as a “regional apocalypse” and imminent flashover—the point of spontaneous combustion in an enclosed space—as “a malevolent entity from another dimension breaking through to this one.”

From Scientific American • Jun. 18, 2023

In this delightfully outrageous tale, Holmes and sidekick John Watson must determine how and why four government officials have died through spontaneous combustion.

From Washington Post • Dec. 17, 2022

This myth about spontaneous combustion would be accepted as scientific fact far longer than might be imagined.

From "1919 The Year That Changed America" by Martin W. Sandler