# fuzz

/ˈfəz/ (US) · /fˈʌz/ (UK)

Source: https://englishreference.com/word/fuzz
Updated: 2026-08-27

## Senses

### 1. soft fibers or hair

noun · CEFR B2

a mass of very fine, soft hair or fibers, like the surface of a peach.

For teachers: a frizzy or fine mass of hair, down, or fiber. Uncountable in its general sense.

- The new sweater left little bits of white fuzz all over my black trousers.
- A fine layer of golden fuzz covered the surface of the ripening fruit, catching the afternoon light.

### 2. the police

noun · CEFR C1 · Slang · Informal

a slang word for the police.

For teachers: a collective slang term for law enforcement officers or agencies. Usually used with the definite article.

- We had to leave the party quickly before the fuzz showed up.
- The protagonist spent the first half of the novel trying to stay one step ahead of the fuzz.

### 3. blurred image or sound

noun · CEFR B2

a blurry quality in a picture or a distorted sound from a guitar.

For teachers: visual blurring or acoustic distortion, particularly the saturated sound produced by an electric guitar.

- The old television had so much fuzz on the screen that I couldn't see the players.
- The guitarist used a vintage pedal to add a heavy layer of fuzz to the opening riff of the song.

### 4. random data

noun · CEFR C1 · Technical

random or messy data used to test if a computer program crashes.

For teachers: randomly generated data used as input for fuzz testing to identify software vulnerabilities.

- The developer used fuzz to see if the new app could handle unexpected inputs.
- After injecting several gigabytes of fuzz into the interface, the security team identified a critical memory leak.

### 5. to make blurry

verb · CEFR B2

to make something look less clear or sharp.

For teachers: to make a visual image or a conceptual boundary blurred or indistinct.

- The steam from the shower started to fuzz the reflection in the mirror.
- The author deliberately chose to fuzz the line between reality and dreams throughout the final chapter.

### 6. to test software

verb · CEFR C1 · Technical

to test a computer program by giving it lots of random information.

For teachers: to perform fuzz testing on a software component by providing it with semi-random data.

- We need to fuzz the new login system to make sure it is secure.
- The QA engineers decided to fuzz the API endpoints for forty-eight hours to ensure maximum coverage of potential edge cases.

## Examples

- The peach has a thin layer of fuzz on its skin.
- The old radio produced a lot of fuzz, making it difficult to hear the news clearly.
- The guitarist intentionally added fuzz to the signal to create a gritty, distorted sound that defined the garage rock genre of the era.

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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.