#filter  device that removes something from whatever passes through it
  supertype:  device  an instrumentality invented for a particular purpose; "the device is small enough to wear on your wrist"; "a device intended to conserve water"
  subtype:  air_filter__airfilter__aircleaner  removes dust from air that passes through it
     subtype:  filter_tip  an air filter on the end of a cigarette; contains material that filters the smoke
  subtype:  bacteria_bed  layer of sand or gravel used to expose sewage effluent to air and the action of microorganisms
  subtype:  coffee_filter  filter (usually of paper) that passes the coffee and retains the coffee grounds
  subtype:  drain_basket__drainbasket  a filter in a sink drain; traps debris but passes water
  subtype:  filter_bed  filter consisting of a layer of sand or gravel for filtering water
  subtype:  fuel_filter  a filter in the fuel line that screens out dirt and rust particles from the fuel
  subtype:  light_filter__lightfilter__diffusing_screen__diffusingscreen  a transparent filter that reduces the light (or some wavelengths of the light) passing through it
  subtype:  oil_filter__oilfilter  a filter that removes impurities from the oil used to lubricate an internal-combustion engine
  subtype:  strainer  a filter to retain larger pieces while smaller pieces and liquids pass through
     subtype:  colander__cullender  bowl-shaped strainer; used to wash or drain foods
     subtype:  sieve__screen  a strainer for separating lumps from powdered material or grading particles
        subtype:  riddle  a coarse sieve (as for gravel)
        subtype:  sifter  a household sieve (as for flour)
     subtype:  tea-strainer__teastrainer  a device to keep back tea leaves when pouring a cup of tea
  subtype:  water_filter__waterfilter  a filter to remove impurities from the water supply
  subtype:  glass_wool__glasswool  glass fibers spun and massed into bundles resembling wool
  subtype:  diatomaceous_earth__diatomite__kieselguhr  a light soil consisting of siliceous diatom remains and often used as a filtering material

No statement uses or specializes filter; click here to add one.