# solenoid

/sˈəʊlənˌɔɪd/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/solenoid
Updated: 2026-10-13

## Definition

a coil of wire that becomes magnetic when electricity flows through it. You find it inside machines like doorbells and car starters, where it pushes or pulls a small metal part.

For teachers: a cylindrical coil of wire that produces a controlled magnetic field when carrying electric current, often surrounding a movable iron core. Energizing the coil draws the core inward to convert electrical energy into short linear motion for switches, valves and starters.

## Examples

- The doorbell uses a small solenoid to make sound.
- The mechanic replaced the faulty starter solenoid so the car engine turns over when you turn the key.
- The laboratory's automated valve relied on a solenoid that, when energized, drew an iron plunger into its core to open the channel in milliseconds.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.