precombustion chamber

noun

: an auxiliary space in which combustible gases are ignited and combustion started ahead of the main combustion chamber of a jet or gas engine

The glow plug is an electrically operated device that protrudes into the precombustion chamber. When energized the glow plug tip heats to a dull red. The swirling, highly compressed air-fuel mixture is heated by the glow plug tip.

—Auto Fundamentals

Word History

First Known Use

1914, in the meaning defined above