spark-plug

A mechanic replaces a spark-plug in a car engine.

Definition

1. Noun:
   • A device in an internal combustion engine that produces a spark to ignite the fuel-air mixture, causing combustion. This is the primary mechanical meaning.
   • (Figuratively) A person or thing that initiates or energizes an activity, event, or process, acting as a catalyst.

Usage Examples

• Noun:
  • The mechanic replaced the old spark-plug to improve the engine's performance. (The mechanical device in the car engine.)
  • She was the spark-plug of the team, always motivating everyone to work harder. (A person who energizes and initiates action in a group.)

Advanced Usage

• "to act as a spark-plug": to serve as the key initiator or motivator in a situation.

  • His speech acted as a spark-plug for the protest movement. (His speech started and energized the movement.)

• "spark-plug of an organization": the person who drives momentum and activity within a group.

  • The new manager became the spark-plug of the company's innovation. (The manager was the catalyst for new ideas.)

Variants and Related Words

• Spark (n/v): a small fiery particle; to produce sparks or initiate something.

  • The spark from the firefly lit up the night. (A small flash of light.)
  • Her comment sparked a heated debate. (Initiated a lively discussion.)

• Plug (n/v): a device for connecting an electrical circuit; to fill or block a hole.

  • He plugged the hole with a cork. (Blocked the opening.)

Synonyms

• Igniter: a device that starts combustion.
• Catalyst: a person or thing that precipitates an event or change.

Idioms

• "to be the spark": to be the person who starts something.

  • He was the spark that ignited the revolution. (He was the initial cause of the revolution.)

• "to spark off": to cause something to start, especially a conflict or chain of events.

  • The argument sparked off a series of protests. (The argument initiated the protests.)

Related Phrases

• Spark-plug wire: the electrical cable connecting the spark-plug to the ignition system.
• Spark-plug gap: the distance between the electrodes of a spark-plug, crucial for proper ignition.