Definition of preignition in English:

preignition

noun

  • The premature combustion of the fuel–air mixture in an internal combustion engine.

    • ‘Early ignition or runaway pre-ignition causes higher combustion chamber temperatures that can wreck the engine.’
    • ‘To run an engine on unleaded fuel it may be necessary to retard the initial timing to prevent detonation and/or pre-ignition.’
    • ‘High-octane fuel simply allows the higher pressures and temperatures in these high-output engines by preventing pre-ignition.’

Pronunciation:

preignition

/ˌprēiɡˈniSH(ə)n/