Wiktionary
glow plug
alt. a device in a diesel engine that heats the combustion chamber to help ignition n. a device in a diesel engine that heats the combustion chamber to help ignition
Wikipedia
Glow plug (model engine)
A glow plug engine, or glow engine, is a type of small internal combustion engine typically used in model aircraft, model cars and similar applications. The ignition is accomplished by a combination of heating from compression, heating from a glow plug and the catalytic effect of the platinum within the glow plug on the methanol within the fuel.