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.
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.
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.
to pass or slip through slowly, as through an obstruction or a filter: Enemy agents managed to filter into the embattled country.
- fil·ter·er, noun
- non·fil·ter, noun
- o·ver·fil·ter, verb (used with object)
- pre·fil·ter, noun
- re·fil·ter, verb (used with object)
- un·fil·ter·ing, adjective
- well-filtered, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use filter in a sentence
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.
We are overwhelmed with data from every quarter, and our capacity to filter fact from fraud is limited.
If users want to send naughty photos with a veil of privacy, opt for the pixilated shower door filter.Swipe Right For Sex: Mixxxer Is Tinder for the Porn Star Set | Aurora Snow | October 4, 2014 | THE 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 | THE DAILY BEAST
Basically, my mother said with a touch of embarrassment, everyone else seemed to have a filter, so they bought one, too.
Somehow, though, I doubt that consumers rush out of the grocery store filter aisle and straight to the testing authorities.
At once cover the mouth of the tube with a filter-paper cap moistened with saturated aqueous solution of silver nitrate (1:1).A Manual of Clinical Diagnosis | James Campbell Todd
In quantitative work the chemist aims to precipitate this green sulphide, which is more easily collected on a filter.The Elements of Qualitative Chemical Analysis, vol. 1, parts 1 and 2. | Julius Stieglitz
The whole is then well stirred, collected on a filter, drained, and dried.Field's Chromatography | George Field
After 24 hours filter the liquor, and evaporate to a pilular consistence.
Dissolve and filter off the liquid from the precipitate, and dilute to proper standard.
British Dictionary definitions for filter
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 pass: See 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
(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
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
Scientific definitions for filter
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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for filter
A computer software program that selectively screens out incoming information.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.