filter

/ˈfɪl.tər/
noun (countable/uncountable)verbIntermediate device or process to remove unwanted parts
⚙️Engineering
technical

A porous device or material that removes unwanted substances from a liquid or gas as it passes through.

The air filter in a car removes dust and pollutants before the air enters the engine.

A component that cleans air before it reaches the engine.

She installed a water filter to remove chlorine from her tap water.

A system that purifies drinking water by removing impurities.

💡

Filters are used in various systems, from household appliances to industrial machinery.

general

A person or thing that selects or excludes something based on certain criteria.

The editor acts as a filter for the most important news stories.

A person who decides which information is relevant or important.

💡

Can be used metaphorically in social, editorial, or technological contexts.

⚙️Engineering
technical

To pass a substance through a filter to remove impurities or unwanted components.

You need to filter the oil before using it in the machine.

To clean or purify a liquid by passing it through a filter.

💡

Common in both mechanical and digital processes (e.g., filtering data).

general

To remove or exclude something unwanted from a group or system.

The company filters out applicants who don’t meet the basic requirements.

To eliminate or reject unsuitable candidates.

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Often used in recruitment, data processing, or content moderation.

Collocations

air filtera device that cleans the air entering an engine or roomwater filtera system that purifies drinking waterfilter outto remove or exclude unwanted elementssocial media filtera digital tool that alters or enhances images/videosfilter feedersaquatic animals that strain food particles from water

Related Phrases

filter throughphrasal verb
to pass gradually or selectively
filter downphrasal verb
to gradually reach lower levels or groups
filter bubblephrase
a state of intellectual isolation due to personalized online content

💡Pro Tip

Common Mistake: 'Filter' vs. 'Strainer'

A 'filter' is typically a passive device (e.g., paper in a coffee maker), while a 'strainer' is an active tool (e.g., mesh spoon) used to separate solids from liquids.

Gold Rule

When to Use 'Filter' as a Verb

Use 'filter' when referring to the process of removing impurities or unwanted elements, especially in technical, digital, or metaphorical contexts (e.g., 'filter noise from data').

Physical vs. Digital Filters

Physical filters (e.g., air filters) remove particles, while digital filters (e.g., email filters) remove unwanted data based on criteria.

📖Word Origin

From Middle English 'filtren' (to filter), from Old French 'filter' (to filter), from Latin 'filtrum' (felt, strainer), possibly of Germanic origin.

📝Usage Notes

The verb 'filter' can be transitive ('filter the water') or intransitive ('the water filters through'). In digital contexts, it often refers to algorithms that process data (e.g., 'filter spam emails').

Word Breakdown

filtr-
Latin root meaning 'felt' or 'strainer'
root
+
-er
suffix indicating a person or thing that performs an action
suffix
English Dictionary