# filter
## English
### Etymology

From Middle English filtre, from Medieval Latin filtrum (compare also Old French feutre (“felt; filter”)), from Frankish *filtir, from Proto-West Germanic *felt. See felt. Doublet of phin.

### Pronunciation

* (Received Pronunciation) IPA: /ˈfɪltə/
* (General American) IPA: /ˈfɪltɚ/
* Audio (US):(file)
* Rhymes: -ɪltə(ɹ)
* Homophone: philter

### Noun

filter (plural filters)
* A device which separates a suspended, dissolved, or particulate matter from a fluid, solution, or other substance; any device that separates one substance from another.
* Electronics or software that separates unwanted signals (for example noise) from wanted signals or that attenuates selected frequencies.
* Any item, mechanism, device, or procedure that acts to separate or isolate.
    He runs an email filter to catch the junk mail.
** 2013 May 25, “No hiding place”, in The Economist‎, volume 407, number 8837, page 74:In America alone, people spent $170 billion on “direct marketing”—junk mail of both the physical and electronic varieties—last year. Yet of those who received unsolicited adverts through the post, only 3% bought anything as a result. If the bumf arrived electronically, the take-up rate was 0.1%. And for online adverts the “conversion” into sales was a minuscule 0.01%. That means about $165 billion was spent not on drumming up business, but on annoying people, creating landfill and cluttering spam filters.
* (figurative) Self-restraint in speech.
    He's got no filter, and he's always offending people as a result.
* (mathematics, order theory) A non-empty upper set (of a partially ordered set) which is closed under binary infima (a.k.a. meets).
    The collection of cofinite subsets of ℝ is a filter under inclusion: it includes the intersection of every pair of its members, and includes every superset of every cofinite set.
    If (1) the universal set (here, the set of natural numbers) were called a "large" set, (2) the superset of any "large" set were also a "large" set, and (3) the intersection of a pair of "large" sets were also a "large" set, then the set of all "large" sets would form a filter.
* (photography) A translucent object placed in the light path of a camera to remove certain wavelengths (colors), or a computer program that simulates such an effect.
* (social media) an appearance-altering digital image effect

#### Antonyms

* (antonym(s) of “order theory”): ideal

#### Hyponyms

* air filter
* Christiansen filter
* cigarette filter
* fuel filter
* glare filter
* Great Filter
* intent filter
* oil filter
* Sobel filter
* sun filter
* ultrafilter

#### Derived terms

* alpha-beta filter
* Bayer filter
* biofilter
* bitfilter
* Bloom filter
* bogon filter
* bozo filter
* Butterworth filter
* chemofilter
* clear-filter
* comb filter
* diafilter
* diesel particulate filter
* dust filter
* electrofilter
* filter bank
* filter bed
* filter bubble
* filter cake
* filter card
* filter coffee
* filter down
* filter feeder
* filter-feeder
* filter funnel
* filtergram
* filter in turn
* filter lane
* filterless
* filterlike
* filterman
* filtermat
* filter pad
* filter paper
* filterplate
* filterset
* filter tip
* filtertop
* filter tube
* filter up
* filterware
* filtrand
* filtrate
* Gabor filter
* Gooch filter
* Great Filter
* haemofilter
* hemofilter
* highpass filter
* interference filter
* interfilter
* intrafilter
* Kalman filter
* killfilter
* leukofilter
* LMS filter
* microfilter
* minifilter
* Mitchell-Netravali filter
* modal filter
* multifilter
* nanofilter
* nonfilter
* notch filter
* (order theory): ultrafilter
* Ormsby filter
* overfilter
* pop filter
* portafilter
* refilter
* Savitzky-Golay filter
* subfilter
* superfilter
* underfilter
* unfilter
* Wiener filter
* wordfilter

#### Descendants

* → Japanese: フィルター (firutā)
* → Korean: 필터 (pilteo)

#### Translations

    The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

### Verb

filter (third-person singular simple present filters, present participle filtering, simple past and past participle filtered)
* (transitive) To sort, sift, or isolate.
    This strainer should filter out the large particles.
** 1954, Alexander Alderson, chapter 5, in The Subtle Minotaur‎:“You have probably never seen anything like this before, Mr. Toler. It is baleen, or if you prefer it, whalebone, taken from the mouth of the bowhead whale. It is used by the whale to filter its food.”
** 1992, Chris C. Bissell, David A. Chapman, Digital signal transmission (2nd edition), Cambridge University Press, →ISBN, page 147:Receivers often incorporate digital equalisers to 'mop up' slight intersymbol interference after initial filtering at the receiver.
** 2022 October 25, Willy Staley, “The Try Guys and the Prison of Online Fame”, in The New York Times Magazine‎:But fans’ emotions are no longer filtered through ticket or album sales; they’re heard directly, constantly, at all hours, on all the platforms people visit to generate and extinguish bad feelings in a never-ending cycle.
* (transitive) To diffuse; to cause to be less concentrated or focused.
    The leaves of the trees filtered the light.
* (intransitive) To pass through a filter or to act as though passing through a filter.
    The water filtered through the rock and soil.
* (intransitive) To move slowly or gradually; to come or go a few at a time.
    The crowd filtered into the theater.
* (intransitive) To ride a motorcycle between lanes on a road
    I can skip past all the traffic on my bike by filtering.
* (intransitive, derogatory, fandom slang) To be discouraged where a connoisseur or hardcore fan would not.
    Most people get filtered by that episode.

#### Synonyms

* (to sort, sift, or isolate) to filter out (something)

#### Derived terms

* defilter
* filterability
* filterable
* filterer
* misfilter
* overfilter
* postfilter
* prefilter
* refilter
* subfilter
* underfilter
* unfilter

#### Translations

    The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

### Related terms

* filtrate
* filtration
* filtride

### Anagrams

* fertil, Trefil, lifter, firtle, relift, filtre, trifle

## Danish
### Noun

filter n (singular definite filtret or filteret, plural indefinite filtre)
* filter

#### Inflection
## Dutch
### Etymology

Borrowed from French filtre or German Filter, from Latin filtrum.

### Pronunciation

* IPA: /ˈfɪl.tər/
* Audio:(file)
* Hyphenation: fil‧ter

### Noun

filter m or n (plural filters, diminutive filtertje n)
* a filter (dense mesh or fabric used for filtration)
* a cigarette filter
* a light filter
* a camera filter

#### Usage notes

The word is masculine in Belgium, chiefly neuter but sometimes masculine in the Netherlands.

#### Derived terms

* filtreren
* filterkoffie
* koffiefilter
* luchtfilter
* sigarettenfilter
* uv-filter
* waterfilter

#### Related terms

* filtratie
* filtreren

#### Descendants

* Afrikaans: filter
* → Indonesian: filter

### References

* ↑ Philippa, Marlies, Debrabandere, Frans, Quak, Arend, Schoonheim, Tanneke, van der Sijs, Nicoline (2003–2009) Etymologisch woordenboek van het Nederlands (in Dutch), Amsterdam: Amsterdam University Press

### Anagrams

* flirte

## German
### Pronunciation

* Audio:(file)

### Verb

filter
* inflection of filtern:
** first-person singular present
** singular imperative

## Hungarian
### Etymology

From German Filter, from Medieval Latin filtrum.

### Pronunciation

* IPA: [ˈfiltɛr]
* Hyphenation: fil‧ter
* Rhymes: -ɛr

### Noun

filter
* filter (any device that separates one substance from another)
* cigarette filter

#### Declension
### References

* ↑ Tótfalusi, István. Idegenszó-tár: Idegen szavak értelmező és etimológiai szótára (’A Storehouse of Foreign Words: an explanatory and etymological dictionary of foreign words’). Budapest: Tinta Könyvkiadó, 2005. →ISBN

## Indonesian
### Etymology

From Dutch filter, from French filtre, from Medieval Latin filtrum (compare also Old French feutre (“felt; filter”)), from Frankish *filtir, from Proto-West Germanic *felt.

### Pronunciation

* IPA: [ˈfɪltər]
* Hyphenation: fil‧têr

### Noun

filter
* filter
** a device which separates a suspended, dissolved, or particulate matter from a fluid, solution, or other substance; any device that separates one substance from another.
** (electronics, physics) electronics or software that separates unwanted signals (for example noise) from wanted signals or that attenuates selected frequencies.

#### Synonyms

* penyaring
* penapis
* tapis

#### Derived terms

* memfilter (“to filter”)

### Further reading

* “filter” in Kamus Besar Bahasa Indonesia, Jakarta: Agency for Language Development and Cultivation – Ministry of Education, Culture, Research, and Technology of the Republic of Indonesia, 2016.

## Kashubian
### Etymology

Borrowed from Polish filtr.

### Pronunciation

* IPA: /ˈfil.tɛr/
* Rhymes: -iltɛr
* Syllabification: fil‧ter

### Noun

filter m inan
* filter (device which separates a suspended, dissolved, or particulate matter from a fluid, solution, or other substance)
    Synonym: czëszcz

### Further reading

* Jan Trepczyk (1994) “filtr”, in Słownik polsko-kaszubski (in Kashubian), volumes 1–2
* Eùgeniusz Gòłąbk (2011) “filtr”, in Słownik Polsko-Kaszubski / Słowôrz Pòlskò-Kaszëbsczi‎

## Norwegian Bokmål
### Etymology

From French filtre.

### Noun

filter n (definite singular filteret or filtret, indefinite plural filter or filtre, definite plural filtra or filtrene)
* filter

#### Derived terms

* kaffefilter
* luftfilter

#### Related terms

* filtrere

### References

* “filter” in The Bokmål Dictionary.

## Norwegian Nynorsk
### Etymology

From French filtre.

### Noun

filter n (definite singular filteret, indefinite plural filter, definite plural filtera)
* filter

#### Derived terms

* luftfilter

### References

* “filter” in The Nynorsk Dictionary.

## Serbo-Croatian
### Alternative forms

* fìltar

### Pronunciation

* IPA: /fǐlter/
* Hyphenation: fil‧ter

### Noun

fìlter m (Cyrillic spelling фѝлтер)
* filter

## Swedish
### Pronunciation

* Audio:(file)

### Noun

filter n
* a filter (similar senses to English)

#### Derived terms

* kaffefilter

### References

* filter in Svensk ordbok (SO)
* filter in Svenska Akademiens ordlista (SAOL)
* filter in Svenska Akademiens ordbok (SAOB)

### Anagrams

* fertil