# thickness

/ˈθɪknəs/ (US) · /θˈɪknəs/ (UK)

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

## Senses

### 1. measurement of depth

noun · CEFR B1

the distance between the front and back or top and bottom surfaces of something.

For teachers: the dimension of an object measured through its smallest side, perpendicular to its length and width.

- The thickness of the walls helps keep the house warm in winter.
- The engineer calculated the required thickness of the steel plating to ensure it could withstand the pressure of the deep-sea environment.

### 2. liquid consistency

noun · CEFR B2

how heavy, solid, or sticky a liquid is.

For teachers: the degree of viscosity or density in a fluid or semi-solid substance.

- Cook the sauce for ten minutes until it reaches the right thickness.
- The chef adjusted the thickness of the gravy by adding a small amount of cornstarch mixed with cold water.

### 3. a layer

noun · CEFR B2

a single layer of a material.

For teachers: a single layer or stratum of a substance, often used when multiple layers are applied.

- Use a double thickness of paper so the ink doesn't bleed through.
- The winter coat featured a triple thickness of insulation, making it suitable for Arctic expeditions.

### 4. lack of intelligence

noun · CEFR C2 · Informal · British English

the quality of being slow to understand things.

For teachers: the state of being intellectually slow or dull-witted.

- I couldn't believe his thickness when he failed to see the obvious joke.
- The manager was often frustrated by the sheer thickness of the new recruits who struggled with basic safety protocols.

Teaching tip: This sense is primarily British and can be quite insulting; use 'slow' or 'unintelligent' in professional contexts.

## Examples

- The thickness of the ice is safe for skating.
- You can adjust the thickness of the slices by turning the dial on the side of the machine.
- Engineers must calculate the precise thickness of the steel hull to ensure the vessel can withstand the immense pressure of deep-sea exploration.

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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.