filter

1 of 2

noun

fil·​ter ˈfil-tər 

1

a

: a porous article or mass (as of paper or sand) through which a gas or liquid is passed to separate out matter in suspension

b

: an apparatus containing a filter medium

2

a

: a device or material for suppressing or minimizing waves or oscillations of certain frequencies (as of electricity, light, or sound)

b

: a transparent material (such as colored glass) that absorbs light of certain wavelengths or colors selectively and is used for modifying light that reaches a sensitized photographic material

called also color filter

3

: something that has the effect of a filter (as by holding back elements or modifying the appearance of something)

his work is too often viewed through the filter of race

—Brent Staples

4

: software for sorting or blocking access to certain online material

filter

2 of 2

verb

filtered; filtering ˈfil-t(ə-)riŋ 

transitive verb

1

: to subject to the action of a filter

2

: to remove by means of a filter

intransitive verb

1

: to pass or move through or as if through a filter

2

: to come or go in small units over a period of time

people began filtering in

Synonyms

Verb

• screen
• strain

Examples of filter in a Sentence

Noun

She smokes cigarettes with filters.

He placed a red filter on the camera lens.

digital filters that stop high-frequency sounds

Verb

They've begun filtering their water to remove impurities.

a device that filters impurities from water

sunglasses that filter ultraviolet light

Sunlight filtered through the leaves.

His ideas have filtered down to his children.

The crowd filtered into the arena.

Early election returns have begun to filter in.

Recent Examples on the Web

Noun

Many creators also have reported that the filters restrict content on other seemingly unrelated topics. —Taylor Lorenz, Washington Post, 10 Apr. 2024

Water passes through the carbon filter before entering the membrane. —Sandee Lamotte, CNN, 10 Apr. 2024

Don’t try viewing the eclipse with alternatives, like sunglasses, binoculars or telescopes without special filters, as inadequate protection can damage your retinas and potentially cause blindness. —Nollyanne Delacruz, The Mercury News, 8 Apr. 2024

Schlitz Audubon Nature Center The Schlitz Audubon Nature Center, 1111 E. Brown Deer Road, is hosting a solar eclipse viewing party from 12:30 to 3:30 p.m. The event will take place in the nature center's veranda and will have a telescope with a solar filter and glasses for safe viewing. —Jordyn Noennig, Journal Sentinel, 8 Apr. 2024

If the filters are coming loose from their cardboard or plastic frames, discard them. —Rong-Gong Lin Ii, Los Angeles Times, 8 Apr. 2024

These glasses feature a solar filter that blocks harmful ultraviolet and infrared radiation, along with intense visible light. —The Arizona Republic, 8 Apr. 2024

The space agency links to a resource page on its site with vetted companies that manufacture and sell safe solar viewers and filters for binoculars and telescopes. —Charlotte Phillipp, Peoplemag, 8 Apr. 2024

While the option to turn off the filter was always available in user settings, many people were not aware Meta made the change. —Sallee Ann Harrison, Quartz, 28 Mar. 2024

Verb

After being gently heated and stirred for up to 14 hours, the mixture is filtered and cooled. —Leah Collins, CNN, 12 Apr. 2024

Their bottles are easy to pack away and can filter out 99.9% of harmful contaminants in most water sources. —Christopher Murray, Fox News, 11 Apr. 2024

Economists expect rent increases to moderate, based on new leases, but that has filtered through just gradually to existing leases. —Paul Davidson, USA TODAY, 10 Apr. 2024

There are several technologies available to purchase to filter PFAS from your home water source. —Tracy J. Wholf, CBS News, 10 Apr. 2024

The unit uses investigative journalism, technical skills, data and other tools to filter through content and determine what is real, and what isn’t, and to explain it to viewers. —Alex Weprin, The Hollywood Reporter, 9 Apr. 2024

Colman envisions a world where scanning for deepfakes is just a regular part of a computer’s cybersecurity software, in the same way that email applications like Gmail now automatically filter out obvious spam. —Gerrit De Vynck, Washington Post, 5 Apr. 2024

Israel said the coordinates never filtered down to the drone operators who fired the missiles. —Tracy Wilkinson, Los Angeles Times, 5 Apr. 2024

On the morning of Sept. 11, Al-Halabi was at breakfast at Travis when word of the attacks filtered out. —Tamara Audi, New York Times, 4 Apr. 2024

Word History

Etymology

Noun

Middle English filtre "felt, felt carpet, piece of felt used as a filter," borrowed from Medieval Latin filtrum "felt cloth, cover or blanket of felt, piece of felt used as a filter," borrowed from *filtir (going back to *filtizō) in a West Germanic language, plural of *filt-, *felt- "felted cloth" — more at felt entry 1

Verb

derivative of filter entry 1

First Known Use

Noun

15th century, in the meaning defined at sense 1a

Verb

1576, in the meaning defined at transitive sense 1

Phrases Containing filter

• color filter
• band-pass filter
• filter tip
• spam filter
• filter paper
• filter bed
• filter feeder
• filter bubble

Kids Definition

filter

1 of 2 noun

fil·​ter ˈfil-tər 

1

: a substance with pores through which a gas or liquid is passed to separate out floating matter

2

: a device containing a filter

3

: a transparent material (as colored glass) that absorbs light of some wavelengths and is used to change light (as in photography)

filter

2 of 2 verb

filtered; filtering -t(ə-)riŋ 

1

: to expose to the action of a filter

2

: to remove by means of a filter

3

: to pass through or as if through a filter

Medical Definition

filter

1 of 2 noun

fil·​ter ˈfil-tər 

1

: a porous article or mass (as of paper or sand) through which a gas or liquid is passed to separate out matter in suspension

2

: an apparatus containing a filter medium

3

a

: a device or material for suppressing or minimizing waves or oscillations of certain frequencies (as of electricity, light, or sound)

b

: a transparent material (as colored glass) that absorbs light of certain wavelengths or colors selectively and is used for modifying light that reaches a sensitized photographic material

called also color filter

filter

2 of 2 verb

filtered; filtering -t(ə-)riŋ 

transitive verb

1

: to subject to the action of a filter

2

: to remove by means of a filter

intransitive verb

: to pass or move through or as if through a filter