[noun] [U]The ignition in an engine is the electrical system that causes the fuel to burn or explode in order to start the engine.Switch/Turn the ignition on.an ignition keySee picture: Car interior(formal) Ignition is also the act or process of something starting to burn.
IGNITION
Meaning of IGNITION in English
Cambridge English vocab. Кембриджский английский словарь. 2012