General English

General Science

  • noun a switch that activates the ignition system of a vehicle or aircraft


  • noun the starting of burning of a substance
  • noun the moment, in an internal combustion engine, when a spark from the spark plug causes the fuel/air mixture to burn
  • noun an electrical system, usually powered by a battery or magneto, that provides the spark to ignite the fuel mixture in an internal-combustion engine

Cars & Driving

  • noun a process which initiates the combustion of the compressed air/fuel mixture in the combustion chamber. In a spark ignition engine, the mixture is ignited by an electric spark; in a diesel engine, the self-igniting mixture must be preheated by glow plugs when a cold start is performed.


  • The raising of the temperature of a substance, such as the fuel mixture in an automobile, to its ignition point.
  • The means utilized to produce ignition (1). This may be accomplished, for instance, electrically or through friction.
  • A switch or other mechanism which activates an ignition system.