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a. A porous material through which a liquid or gas is passed in order to separate the fluid from suspended particulate matter.
b. A device containing such a material, especially one used to extract impurities from air or water.
a. Any of various electric, electronic, acoustic, or optical devices used to reject signals, vibrations, or radiations of certain frequencies while allowing others to pass.
b. A colored glass or other transparent material used to select the wavelengths of light allowed to reach a photosensitive material.
3. Computers A program or device that blocks email or restricts website access when specific criteria are met.
4. Informal The ability or tendency to censor oneself, as to avoid causing embarrassment or offense: My roommate has no filter and says whatever he's thinking at the moment.
v. fil·tered, fil·ter·ing, fil·ters
1. To pass (a liquid or gas) through a filter.
2. To remove by passing through a filter: filter out impurities.
3. Computers To use a filter to block or restrict access to: a program that filters spam.
4. Informal To censor (oneself), as to avoid causing embarrassment or offense.
1. To pass through or as if through a filter: Light filtered through the blinds.
2. To come or go gradually and in small groups: The audience filtered back into the hall.

[Middle English filtre, from Old French, from Medieval Latin filtrum, of Germanic origin; see pel- in Indo-European roots.]

fil′ter·er n.
fil′ter·less adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


The process of interpreting reported information on movements of aircraft, ships, and submarines in order to determine their probable true tracks and, where applicable, heights or depths.
Dictionary of Military and Associated Terms. US Department of Defense 2005.


n. filtración, el acto de filtrar a través de un filtro que impide el paso de ciertas moléculas;
___ operationoperación de ___.
English-Spanish Medical Dictionary © Farlex 2012
References in classic literature ?
Daylight was filtering into the well from the orifice far above his head.
Now the cottage stood by the edge of a great green forest where the wind was always singing in the branches and the sunshine filtering through the leaves.
Through half open lids she saw the sunlight filtering through the leafy canopy above her--she wondered at the realism of her dream; full consciousness returned and with it the conviction that she was in truth being held close by strong arms against a bosom that throbbed to the beating of a real heart.
When next I awoke, a sickly yellow light was filtering in on me.
Automotive filters are devices composed of filtering materials that remove impurities in engine fluids, and also prevent the entry of contaminants.
Properly filtering iron castings involves utilizing the most optimally engineered filter print and gating system designs to ensure delivery of the cleanest and least turbulent metal to the mold cavity.
With this method, a signal is also processed several times with the same filter, but the output signal is formed from the input signal and other filtering stages output signals in a specific order.
Several research groups have been working in this direction to promote the development of a real filtering technology [2,3,5,6].
Some argue that surface-loading pa-per elements are more restrictive to airflow by design because the filtering fiber must be tightly compressed and dense enough to effectively trap the harmful contaminates.
It is best to eliminate as many contaminants sources as possible before filtering them.
Pleating of the filter media provides a larger filtering surface area within a given space than with panel filters.