spark plug


: 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
: one that initiates or gives impetus to an undertaking
sparkplug transitive verb

Example Sentences

Recent Examples on the Web On a night that was technically a Clippers home game, cheers grew after former Clippers spark plug Beverley, who didn’t give an inch while defending George in the second quarter, yelling at his former teammate after George passed the ball. Andrew Greif, Los Angeles Times, 9 Nov. 2022 Marcy Kaptur, whose mother was a union organizer at a spark plug plant, will likely hold her Toledo-area House seat after her MAGA opponent lied about his military record. Alec Macgillis, ProPublica, 21 Oct. 2022 Williams took it upon himself to be the spark plug, jolting the group to life and calling on his teammates to get their act together. Ryan Kartje, Los Angeles Times, 25 Aug. 2022 That odd sonic signature is almost diesel-like and seemingly a product of the six cylinders' dual combustion chambers, each with its own spark plug. Mike Duff, Car and Driver, 25 Oct. 2022 This can potentially damage the spark plug and generally does not allow the generator to run smoothly. Kat De Naoum, Better Homes & Gardens, 26 Sep. 2022 Danta then lost a spark plug wire and had to pull off. Tony Baranek, Chicago Tribune, 9 Sep. 2022 Don’t sleep on this team that found talent at running back in 5-foot-8 spark plug Calvin Tyler and at wide receiver in jitterbug, 5-foot-7 Robert Briggs. Joseph Goodman |, al, 1 Sep. 2022 Steinberg holds up a small plastic wing attached to a metal piece shaped like a spark plug. Dominic Smith, Scientific American, 7 Sep. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'spark plug.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

First Known Use

1903, in the meaning defined at sense 1

Time Traveler
The first known use of spark plug was in 1903

Dictionary Entries Near spark plug

Cite this Entry

“Spark plug.” Dictionary, Merriam-Webster, Accessed 8 Dec. 2022.

Kids Definition

spark plug

: a device used in an engine to produce a spark that ignites a fuel mixture
: one that begins something or drives something forward

More from Merriam-Webster on spark plug

Last Updated: - Updated example sentences
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