[mass noun] The ignition of organic matter (e.g. hay or coal) without apparent cause, typically through heat generated internally by rapid oxidation.
- ‘To better ventilate the haymows and prevent spontaneous combustion of freshly cut hay, he designed the side walls of two of the barns to end about 3 feet below the eaves.’
- ‘Investigators have ruled out any form of spontaneous combustion of the chemical, which is known to be relatively stable in the absence of any detonator.’
- ‘There were no arrows of fire, only a spontaneous combustion from within the huts and houses.’