Definition

Noun: 1. A device for igniting the fuel mixture in an internal-combustion engine: A spark plug is an electrical device screwed into the cylinder head of an engine. Its core function is to produce an electric spark to ignite the compressed air-fuel mixture, initiating the combustion that powers the engine.

Usage

The term "spark plug" is used to refer to the specific engine component. It is a countable noun. * Mechanics check and replace worn spark plugs during a tune-up. * The engine misfired because one spark plug was faulty. * A common maintenance task is changing the spark plugs.

Advanced Usage

• Figurative Use - "The spark plug of the team": Informally, a person who provides energy, impetus, or inspiration to a group can be called its "spark plug."
  • The young midfielder was the spark plug for the team's offensive plays.

Variants and Related Words

• Spark plug gap (noun phrase): The precise distance between the center and ground electrodes of a spark plug, which is critical for proper spark generation.
• Spark plug wrench (noun phrase): A special socket wrench designed for removing and installing spark plugs.
• Igniter/Ignition device (noun): A more general term for any device that starts combustion.

Synonyms

• Plug (noun): A common shortened form in automotive contexts (e.g., "I need to change the plugs").
• Ignition plug (noun): A less common, more descriptive synonym.

Related Idioms and Phrases

• To foul a spark plug (verb phrase): When a spark plug becomes coated with oil, carbon, or fuel deposits, preventing it from sparking properly. This can be used literally or figuratively for something that impedes function.
  • The rich fuel mixture fouled the spark plugs. (Literal)
  • Constant negativity fouled the spark plugs of our project's momentum. (Figurative)

Noun

1. electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark