ignition

1. The act of igniting. (countable, uncountable)
2. The initiation of combustion. (countable, uncountable)
3. A system for activating combustion in a combustion engine. (countable, uncountable)
4. Receptacle for a key used to start the engine in a vehicle. (countable, uncountable) · Put the key in the ignition and turn it right.
5. The phenomenon of a thermonuclear fusion reaction becoming self-sustaining and no longer requiring external heating. (countable, uncountable)

Plural ignitions