ignition system definition
ignition. Use ignition in a sentence. LINK / CITE ADD TO WORD LIST. noun. The ignition switch in an automobile. The ignition switch in an automobile. The definition of an ignition is a system or device that sets something on fire. An example of an ignition is what turns your car's engine on when you turn the key. 1  a setting on fire or catching on fire. 2  the means by which a thing is ignited. 3  in an internal-combustion engine,