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

Player of the Week Junior infielder Emma Gelecke is an offensive spark plug for Shepard, going 3-for-4 with four runs, five singles and a double in back-to-back games. —Tony Baranek, Chicago Tribune, 5 May 2026

The defensive spark plug somehow jumped higher than any Nuggets forward did for a rebound in Minneapolis last Thursday night, chest-thumping the glass at the top of his leap. —Sean Keeler, Denver Post, 4 May 2026

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, 2 May 2026

My mechanic already replaced the computer, distributor cap, rotor, spark plugs, and wires. —Hartford Courant, 25 Apr. 2026

Word History

First Known Use

1903, in the meaning defined at sense 1

Rhymes for spark plug

• debug
• humbug
• prodrug
• unplug
• antidrug
• mealybug
• multidrug
• chug
• doug
• drug
• dug
• hug

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