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.
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
Even when they’re available, portable air filters can be expensive, easily costing up to several hundred dollars for a device big enough to clean the air in a single room.
Wildfire smoke and COVID-19 are a one-two punch for indoor air quality across the U.S.|dzanemorris|September 17, 2020|Fortune
Hmmm, Google already had a filter set to not pass all Search Terms into the UI based on traffic volume, so this appears to be them simply moving the threshold.
How much does Google’s new search term filtering affect ad spend transparency? Here’s how to find out|Frederick Vallaeys|September 16, 2020|Search Engine Land
Once the nearby filter is selected, users will see a new UI that Google is calling a “local stores card,” also constructed of local inventory data from merchant feeds.
Google boosting visibility of ‘nearby’ product inventory with new Shopping features|Greg Sterling|September 16, 2020|Search Engine Land
In a blog post in 2016, it detailed what went into the system’s design, along with testing data to back up its claims of a HEPA filter that’s “ten times more efficient than standard automotive filters.”
Elon Musk says Tesla will ‘one day’ produce ‘super efficient home HVAC’ with HEPA filtering|Darrell Etherington|September 11, 2020|TechCrunch
So this fall, classrooms might get new air filters that weren’t there before.
Here’s how COVID-19 is changing classes this year|Bethany Brookshire|September 8, 2020|Science News For Students
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.
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
Britisha 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
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.
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.