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English definition of “spark plug”

spark plug

noun [C] uk   us  

spark plug noun [C] (ENGINE)

a device in an engine that produces an electrical spark that lights the fuel and makes the engine start

spark plug noun [C] (PERSON)

US a person who gives energy to an activity involving others: She's the spark plug of the team.
(Definition of spark plug from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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