spark plug

noun

a device designed to fit in each cylinder of a gasoline-powered internal-combustion engine and to produce the electric spark for igniting the mixture of gasoline and air.

Informal. a person who leads, inspires, or animates a group.

Origin

1900-05

Examples from the web for spark plug

The fuel is directed straight at the spark plug, rather than at the cylinder wall.
When the piston returns upward in the compression cycle, the spark plug emits a spark to ignite the fuel-air mixture.
If spark plug is wet with fuel, the engine could be flooded.
In a spark-ignition engine, the mixture is ignited by a spark from the spark plug, releasing heat.
Changed the spark plug, filled and run the emergency back up generator.
And you would have the spark plug there for backup, but if you don't need it, you increase your efficiency.
Government is not the answer, but wise fiscal policy-focused on investment-is a spark plug when activity sputters.
In sports, it's good to be referred to as a spark plug.
Unfortunately, increased spark energy negatively impacts spark plug durability and performance as an ignition source.
spark plug electrode wear may greatly limit the advancement of natural gas reciprocating engines technologies.

British Dictionary definitions for spark plug

spark plug

noun

another name for sparking plug

spark plug in Science

spark plug

A device in the cylinder head of an internal-combustion engine that ignites the fuel mixture by means of an electric spark. Spark plugs consist of two electrodes that are separated by an insulator except at their tips. When high voltage electricity is fed to one electrode, it jumps across the gap from one tip to the other as a spark. The voltage required to generate a spark is directly proportional to the size of the gap; in a car engine it is about 18,000 volts.

Slang definitions & phrases for spark plug

spark

verb

To initiate and stimulate; trigger: Willy Mays sparked an eighth inning Giant drive by stealing second (1912+)