# thin

/ˈθɪn/ (US) · /θˈɪn/ (UK)

Source: https://englishreference.com/word/thin
Updated: 2026-08-15

## Senses

### 1. not thick

adjective · CEFR A2

having a small distance between two sides; not thick.

For teachers: having little thickness or extent from one surface to its opposite.

- The ice on the lake is too thin to walk on safely.
- The artisan used a thin blade to carve the intricate patterns into the delicate wooden box.

### 2. body weight

adjective · CEFR A2

having little fat on the body.

For teachers: having little body fat or flesh; lean or slender in build.

- He became very thin after being sick for two weeks.
- The marathon runner had a thin, wiry frame that was perfectly suited for long-distance endurance.

### 3. liquid or air

adjective · CEFR B1

flowing easily like water; not thick or sticky.

For teachers: of low viscosity or density; lacking substance or volume.

- The air is very thin at the top of the mountain.
- The sauce was too thin, so the chef decided to simmer it for another ten minutes to reduce the liquid.

### 4. not crowded

adjective · CEFR B2

having only a few people or things in a large space.

For teachers: distributed at wide intervals; not dense or crowded.

- The crowd at the stadium was thin because of the heavy rain.
- Vegetation becomes thin as you move further into the desert, with only a few hardy shrubs surviving the heat.

### 5. to make less dense

verb · CEFR B2

to make something thinner or to reduce the number of things in a group.

For teachers: to make or become thin or thinner in consistency or density; often used with 'out'.

- You should thin the carrots so the remaining ones have room to grow.
- The traffic began to thin out after the morning rush hour ended and the commuters reached their offices.

Usage: Often used as the phrasal verb 'thin out' when referring to crowds or plants.

### 6. in a thin way

adverb · CEFR B2

in a way that is not thick.

For teachers: in a scattered or sparse manner; not thickly.

- Spread the butter thin on the toast so it is not too greasy.
- The paint was applied so thin that the grain of the wood was still visible underneath.

## Examples

- You should thin the paint with a little water.
- The gardener needs to thin out the carrots so the remaining ones have enough room to grow large.
- As the hikers climbed higher into the mountains, the oxygen began to thin, making every step feel significantly more exhausting than it had at sea level.

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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.