Definition of pre-combustion in English:

pre-combustion

noun

  • In some diesel engines: commencement of combustion of the fuel in an auxiliary chamber, before it is drawn into the main cylinder. Compare prechamber.

Origin

1920s. From pre- + combustion.

Pronunciation

pre-combustion

/ˌpriːkəmˈbʌstʃ(ə)n/