top definitions
quizzes
related content
examples
explore dictionary
british
medical
scientific
cultural

filter

[ fil-ter ]

/ ˈfɪl tər /

SEE SYNONYMS FOR filter ON THESAURUS.COM

noun

any substance, as cloth, paper, porous porcelain, or a layer of charcoal or sand, through which liquid or gas is passed to remove suspended impurities or to recover solids.

any device, as a tank or tube, containing such a substance for filtering.

any of various analogous devices, as for removing dust from air or impurities from tobacco smoke, or for eliminating certain kinds of light rays.

something that works like a filter, as by removing, blocking, or separating out certain elements: Kids often talk without a filter. Events can be distorted through the filter of memory.

Informal. a filter-tipped cigarette or cigar.

Photography.

a lens screen of dyed gelatin or glass placed on a camera for controlling the rendering of color or for diminishing the intensity of light.
Digital Technology. a data manipulation function that changes the color or sharpness of a digital image or overlays an additive or special effect element: Use a sepia filter to give your photos that old-timey look.

Electronics, Physics. a circuit or device that passes certain frequencies and blocks others.

Mathematics. a collection of subsets of a topological space, having the properties that the intersection of two subsets in the collection is a subset in the collection and that any set containing a subset in the collection is in the collection.

Computers. an algorithm that categorizes, sorts, prioritizes, or blocks data through rule-based protocols: an email filter that deletes messages with subject words found commonly in spam.

verb (used with object)

to remove by the action of a filter.

Computers. to subject (data) to an algorithmic filter: The search engine will filter your query results based on your location and user profile.

to act as a filter for; to slow or partially obstruct the passage of: The thick leaves filtered the sunlight.

to pass through or as through a filter.

verb (used without object)

to pass or slip through slowly, as through an obstruction or a filter: Enemy agents managed to filter into the embattled country.

QUIZZES

WHO SAID IT: A QUIZ ON PRESIDENTIAL WIT AND WISDOM

Think you know your presidents? Take this quiz and see if you can match the style, wit, and ideology of these memorable lines to the right POTUS.

Question 1 of 9

“I do believe that the buck stops here, that I cannot rely upon public opinion polls to tell me what is right. I do believe that right makes might and that if I am wrong, 10 angels swearing I was right would make no difference.”

TAKE THE QUIZ TO FIND OUT

Origin of filter

First recorded in 1375–1425; late Middle English filtre, from Medieval Latin filtrum “felt, piece of felt used to strain liquids,” from Germanic; see origin at felt²

SYNONYMS FOR filter

14 penetrate, sift, seep, trickle, leak.

SEE SYNONYMS FOR filter ON THESAURUS.COM

OTHER WORDS FROM filter

fil·ter·er, nounnon·fil·ter, nouno·ver·fil·ter, verb (used with object)pre·fil·ter, noun

re·fil·ter, verb (used with object)un·fil·ter·ing, adjectivewell-filtered, adjective

Words nearby filter

filoselle, filosus, filovirus, fils, filt., filter, filterable, filterable virus, filter bed, filter bubble, filter cake

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for filter

The PuriCare Wearable Air Purifier employs two H13 HEPA filters, similar to the filters used in the company’s home air purifier products.
LG is releasing a ‘wearable air purifier’|Brian Heater|August 27, 2020|TechCrunch
Chrome introduced a filter in 2018 to automatically filter out pages with ads that don’t meet the Coalition’s standards.
Google Chrome’s new ‘heavy ads’ blocker catches some publishers by surprise|Lara O'Reilly|August 26, 2020|Digiday
Thanks to better technology and pressure from regulators, ionizing filters that don’t generate ozone are now available, and the California Air Resources Board has created a list of those that emit only safe levels of ozone.
Can an air purifier help protect you from COVID-19?|dzanemorris|August 22, 2020|Fortune
Outfits like the Manufacturing Solutions Center are also uniquely qualified to develop a new generation of higher-performance cloth masks, or ones that use small filter inserts to stretch scarce materials further.
Unmade in America|Tate Ryan-Mosley|August 14, 2020|MIT Technology Review

The idea behind all these air changes and filters is to dilute and clean the air so that aerosols can’t build up into high concentrations.
How To Make Indoor Air Safer|Kaleigh Rogers (kaleigh.rogers@fivethirtyeight.com)|July 20, 2020|FiveThirtyEight
We are overwhelmed with data from every quarter, and our capacity to filter fact from fraud is limited.
The Facts About Ferguson Matter, Dammit|Doug McIntyre|December 3, 2014|DAILY BEAST
By using some sort of filter—like, perhaps, a universally understood saying—the trait is more easily conveyed.
Scotland’s ‘Yes’ Campaign and the Myth of Scottish Equality|Noah Caldwell|September 18, 2014|DAILY BEAST
Basically, my mother said with a touch of embarrassment, everyone else seemed to have a filter, so they bought one, too.
Are Water Filters B.S.?|Michael Schulson|August 19, 2014|DAILY BEAST
According to the box, the filter will provide me with better-tasting water.
Are Water Filters B.S.?|Michael Schulson|August 19, 2014|DAILY BEAST
You research a world, and then you filter the results to fit a story.
Writing a Novel: Even Making It Up Requires Research|Ridley Pearson|July 16, 2014|DAILY BEAST
Expose again to sunlight, filter, and bath is ready for use.
Cooley's Practical Receipts, Volume II|Arnold Cooley
The fluid may be poured into the filter itself, and used in the ordinary manner.
The Art and Practice of Silver Printing|H. P. Robinson
The form of precipitation generally adopted was to add sulphate of iron to the liquid drawn from the filter.
Scientific American Supplement, No. 620, November 19,1887|Various
Put the paste, back in the grinder or in the mortar, grind or pound again, then filter again with another third of the water.
The Italian Cook Book|Maria Gentile
Through the filtrate pass a rapid current of sulphuretted hydrogen, allow to settle, and filter.
A Textbook of Assaying: For the Use of Those Connected with Mines.|Cornelius Beringer and John Jacob Beringer

British Dictionary definitions for filter

filter

/ (ˈfɪltə) /

noun

a porous substance, such as paper or sand, that allows fluid to pass but retains suspended solid particles: used to clean fluids or collect solid particles

any device containing such a porous substance for separating suspensions from fluids

any of various porous substances built into the mouth end of a cigarette or cigar for absorbing impurities such as tar

any electronic, optical, or acoustic device that blocks signals or radiations of certain frequencies while allowing others to passSee also band-pass filter

any transparent disc of gelatine or glass used to eliminate or reduce the intensity of given frequencies from the light leaving a lamp, entering a camera, etc

British a traffic signal at a road junction consisting of a green arrow which when illuminated permits vehicles to turn either left or right when the main signals are red

verb

(often foll by out) to remove or separate (suspended particles, wavelengths of radiation, etc) from (a liquid, gas, radiation, etc) by the action of a filter

(tr) to obtain by filtering

(intr foll by through) to pass (through a filter or something like a filter)dust filtered through the screen

(intr) to flow slowly; trickle

Word Origin for filter

C16 filtre from Medieval Latin filtrum piece of felt used as a filter, of Germanic origin; see felt ²

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for filter

filter

[ fĭl′tər ]

n.

A porous material through which a liquid or gas is passed in order to separate the fluid from suspended particulate matter.

A device containing such a substance.

Any of various electric, electronic, acoustic, or optical devices used to reject signals, vibrations, or radiations of certain frequencies while passing others.

A translucent screen, used in both diagnostic and therapeutic radiology, that permits the passage of rays having desirable levels of energy.

A device used in spectrophotometric analysis to isolate a segment of the spectrum.

v.

To pass a liquid or gas through a filter.

To remove by passing through a filter.

To pass through or as if through a filter.

Scientific definitions for filter

filter

[ fĭl′tər ]

A material that has very tiny holes and is used to separate out solid particles contained in a liquid or gas that is passed through it.

A device that allows signals with certain properties, such as signals lying in a certain frequency range, to pass while blocking the passage of others. For example, filters on photographic lenses allow only certain frequencies of light to enter the camera, while polarizing filters allow only light polarized along a given plane to pass. Radio tuners are filters that allow frequencies of only a narrow range to pass into an amplification circuit.

Cultural definitions for filter

filter

A computer software program that selectively screens out incoming information.

notes for filter

Spam may be the target of a filter, or parents may use a filter designed to prevent their child's access to pornographic or violent Web pages.

MEANINGS

WORD GAMES

LEARN

WRITING

WORD OF THE DAY

filter

noun

verb (used with object)

verb (used without object)

QUIZZES

WHO SAID IT: A QUIZ ON PRESIDENTIAL WIT AND WISDOM

Origin of filter

SYNONYMS FOR filter

OTHER WORDS FROM filter

Words nearby filter

Example sentences from the Web for filter

British Dictionary definitions for filter

noun

verb

Word Origin for filter

Medical definitions for filter

n.

v.

Scientific definitions for filter

Cultural definitions for filter

notes for filter

MEANINGS

WORD GAMES

LEARN

WRITING

WORD OF THE DAY

filter

noun

verb (used with object)

verb (used without object)

QUIZZES

WHO SAID IT: A QUIZ ON PRESIDENTIAL WIT AND WISDOM

Origin of filter

SYNONYMS FOR filter

OTHER WORDS FROM filter

Words nearby filter

Words related to filter

Example sentences from the Web for filter

British Dictionary definitions for filter

noun

verb

Word Origin for filter

Medical definitions for filter

n.

v.

Scientific definitions for filter

Cultural definitions for filter

notes for filter