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 Friday’s 8-2 victory over the Baltimore Orioles, Garcia was the spark plug for the Royals offense. —Jaylon Thompson, Kansas City Star, 5 Apr. 2025

Mazda’s solution is to create a region near the spark plug that’s just a bit too lean to catch fire by compression alone. —IEEE Spectrum, 30 July 2018

Now, two weeks into the 2025 season, McKinstry is again serving as a tangible spark plug and an emotional catalyst. —Cody Stavenhagen, New York Times, 13 Apr. 2025

The Upshot Of A Student Loan Incentive Does a $500 incentive plan offer a creative spark plug as America's student loan machine returns to life? —Shahar Ziv, Forbes.com, 4 Apr. 2025

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