# coil

/ˈkɔɪɫ/ (US) · /kˈɔɪl/ (UK)

Source: https://englishreference.com/word/coil
Updated: 2026-06-20

## Senses

### 1. a spiral shape

noun · CEFR B2

a length of something like rope or wire wound into a series of loops.

For teachers: a series of connected spirals or concentric rings formed by winding a flexible material.

- The sailor left a neat coil of rope on the deck of the boat.
- The heavy steel cable was stored in a massive coil to prevent it from kinking during transport to the construction site.

### 2. electrical component

noun · CEFR C1 · Technical

a wire wound into a spiral that carries electricity.

For teachers: a length of conductive wire wound into a spiral to create magnetic induction or resistance within a circuit.

- The mechanic had to replace the ignition coil because the car wouldn't start.
- The copper coil within the transformer had overheated, causing a short circuit that disabled the entire server rack.

### 3. medical device

noun · CEFR C1 · British English

a small device placed inside a woman's body to prevent pregnancy.

For teachers: an intrauterine device (IUD) used for long-term contraception, historically named for its spiral shape.

- She went to the clinic to discuss having a coil fitted.
- The patient requested the removal of her contraceptive coil after experiencing persistent side effects over several months.

### 4. to wind up

verb · CEFR B2

to twist or wind something into a spiral or loops.

For teachers: to wind a flexible material into a series of loops or a helical shape.

- The snake started to coil its body before it moved toward the grass.
- The climbers carefully coiled their ropes after reaching the summit to ensure they would be ready for the descent.

### 5. a wad of money

noun · CEFR C2 · Slang · Informal

a roll or thick pile of paper money.

For teachers: a significant quantity of banknotes rolled or folded together.

- He pulled a thick coil of cash out of his pocket to pay for the dinner.
- The informant produced a coil of hundred-dollar bills, claiming it was only a fraction of the total payment promised.

## Examples

- The snake lay in a tight coil on the warm rock.
- The technician replaced the ignition coil to fix the engine's recurring starting problem.
- A thick coil of copper wire sat on the workbench, ready to be wound into the transformer for the new power supply unit.

---

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.