n.
Pronunciation: ig- ' ni-sh ə n
Function: noun
Date: 1612
1 : the act or action of igniting: as a : the starting of a fire b : the heating of a plasma to a temperature high enough to sustain nuclear fusion
2 a : the process or means (as an electric spark) of igniting a fuel mixture b : a device that activates an ignition system (as in an automobile) <put the key in the ignition >