spark plug

noun

1

: a part that fits into the cylinder head of an internal combustion engine and carries two electrodes separated by an air gap across which the current from the ignition system discharges to form the spark for combustion

2

: one that initiates or gives impetus to an undertaking

sparkplug

ˈspärk-ˌpləg 

transitive verb

Examples of spark plug in a Sentence

Recent Examples on the Web

In a gas engine, a small device called a spark plug ignites the compressed fuel-air mixture. —Michael Leamy, Discover Magazine, 2 Nov. 2024

Step 2: Turn Off Mower: After 15 minutes turn off the engine, then disconnect the spark plug to avoid accidentally starting the mower during the oil change. —Timothy Dale, Better Homes & Gardens, 12 Oct. 2024

Just like your car, your lawn mower occasionally needs maintenance in the form of new spark plugs, an oil change, new tires, and a new air filter. —Kamron Sanders, Better Homes & Gardens, 28 Sep. 2024

When the wire is disconnected, carefully turn the spark plug counterclockwise to loosen and remove it. —Timothy Dale, Better Homes & Gardens, 27 Sep. 2024

Word History

First Known Use

1903, in the meaning defined at sense 1

Kids Definition

spark plug

noun

1

: a device used in an engine to produce a spark that ignites a fuel mixture

2

: one that begins something or drives something forward