# filter

/ˈfɪɫtɝ/ (US) · /fˈɪltɐ/ (UK)

Source: https://englishreference.com/word/filter
Updated: 2026-06-19

## Senses

### 1. cleaning device

noun · CEFR B1

a device that removes dirt or unwanted pieces from a liquid or gas.

For teachers: a porous device or substance used to separate suspended particulate matter from a fluid.

- You need to change the water filter every six months to keep the water clean.
- The industrial ventilation system utilizes a high-efficiency particulate air filter to ensure the laboratory remains free of contaminants.

Usage: often used with 'water', 'air', or 'coffee' as a modifier.

### 2. digital image effect

noun · CEFR A2

a software tool that changes how a photo or video looks, often used on social media.

For teachers: a digital image processing effect that alters the appearance of a photograph or video stream.

- She used a vintage filter to make her new photos look like they were from the 1970s.
- Social media platforms offer a variety of augmented reality filters that can modify facial features in real-time during video calls.

### 3. self-restraint in speech

noun · CEFR B2 · Informal

the ability to think before you speak so you do not say something rude or inappropriate.

For teachers: the psychological or social capacity for self-censorship and restraint in verbal communication.

- Sometimes he says exactly what he thinks because he has no filter.
- In casual settings, her lack of a social filter is charming, but it can be problematic during formal business negotiations.

Usage: usually used with 'no' or 'a' in phrases like 'he has no filter'.

### 5. to remove unwanted parts

verb · CEFR B1

to pass a liquid or gas through a device to clean it.

For teachers: to pass a substance through a medium to remove impurities or specific components.

- The sunlight was filtered by the thick leaves of the trees.
- The kidneys work constantly to filter waste products from the blood and maintain chemical balance.

### 6. to move slowly

verb · CEFR B2

to move or spread slowly, often a few people or things at a time.

For teachers: to move, seep, or communicate gradually or in small quantities.

- News about the company's closing began to filter out to the employees.
- After the concert ended, the audience began to filter out of the stadium and into the nearby subway stations.

Usage: often used with prepositions like 'through', 'in', or 'out'.

### 7. to ride between lanes

verb · CEFR C1 · British English

to ride a motorcycle or bicycle between lanes of slow-moving cars.

For teachers: to navigate a two-wheeled vehicle between lanes of stationary or slow-moving traffic.

- The motorcyclist filtered through the heavy traffic to reach the front of the queue.
- While filtering is legal in many jurisdictions, riders must exercise extreme caution when passing between large commercial vehicles.

## Examples

- You should change the water filter every three months.
- She applied a vintage filter to the photo before posting it to her social media profile.
- The network administrator updated the spam filter to prevent malicious attachments from reaching the employees' inboxes during the phishing wave.

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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.