# fil

/ˈfɪɫ/ (US) · CEFR C2 · Noun

Source: https://englishreference.com/word/fil
Updated: 2026-05-06

## Definition

a very thin thread or wire. It is often used to describe the delicate parts of a spider's web or a light bulb.

For teachers: a slender, threadlike object or fiber, such as those found in animal or plant structures or the wire in an incandescent lamp.

## Examples

- The spider hung from a single fil of silk.
- The jeweler used a tiny fil of gold to repair the delicate antique necklace.
- In the early days of electrical engineering, inventors experimented with various carbonized materials to find a fil that could withstand high heat without breaking.

## Usage notes

- Often used in technical or literary contexts to describe extreme thinness.

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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.