Filter

//ˈfɪltə// name, noun, verb, slang

name, noun, verb, slang ·Common ·Middle school level

Definitions

Noun
  1. 1
    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.

    "Then add four drops of crocodile semen, and pass the mixture through a filter."

  2. 2
    device that removes something from whatever passes through it wordnet
  3. 3
    Electronics or software that separates unwanted signals (for example noise) from wanted signals or that attenuates selected frequencies.
  4. 4
    an electrical device that alters the frequency spectrum of signals passing through it wordnet
  5. 5
    Any item, mechanism, device, or procedure that acts to separate or isolate.

    "He runs an email filter to catch the junk mail."

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  1. 6
    Self-restraint in speech. figuratively

    "He's got no filter, and he's always offending people as a result."

  2. 7
    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."

  3. 8
    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.
  4. 9
    An appearance-altering digital image effect.

    "He don't need no filter posting pictures!"

Verb
  1. 1
    To sort, sift, or isolate. transitive

    "This strainer should filter out the large particles."

  2. 2
    pass through wordnet
  3. 3
    To diffuse; to cause to be less concentrated or focused. transitive

    "The leaves of the trees filtered the light."

  4. 4
    remove by passing through a filter wordnet
  5. 5
    To pass through a filter or to act as though passing through a filter. intransitive

    "The water filtered through the rock and soil."

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  1. 6
    run or flow slowly, as in drops or in an unsteady stream wordnet
  2. 7
    To move slowly or gradually; to come or go a few at a time. intransitive

    "The crowd filtered into the theater."

  3. 8
    To ride a motorcycle between lanes on a road intransitive

    "I can skip past all the traffic on my bike by filtering."

  4. 9
    To be discouraged where a connoisseur or hardcore fan would not. derogatory, intransitive, slang

    "Most people get filtered by that episode."

Proper Noun
  1. 1
    A surname from German.

Synonyms

All synonyms
percolatetricklebleedboltbutterflycheesecloth

Antonyms

All antonyms
ideal

Example

More examples

"In swimming pools, water is continuously pumped through a filter."

Etymology

Etymology 1

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.

Etymology 2

Borrowed from German Filter.

Related phrases

Bayer filterBloom filterButterworth filterGabor filterGooch filterGreat FilterKalman filterLMS filterMitchell-Netravali filterOrmsby filterSavitzky-Golay filterWiener filter

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.