filter

fil•ter

[[t]ˈfɪl tər[/t]] n.

1) chem. any substance, as cloth, paper, porous porcelain, or charcoal, through which liquid or gas is passed to remove suspended impurities or to recover solids

2) chem. any device, as a tank or tube, containing such a substance for filtering

3) chem. any of various analogous devices, as for removing dust from air or impurities from tobacco smoke

4) inf Informal. a filter-tipped cigarette or cigar

5) pht a lens screen of dyed gelatin or glass used in photography to control the rendering of color or to diminish the intensity of light

6) elo an electronic circuit or device that passes certain frequencies and blocks others

7) to remove by the action of a filter

8) to act as a filter for; to slow or partially obstruct the passage of

9) to pass through or as if through a filter

10) to pass or slip through slowly, as through an obstruction or a filter; penetrate

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Etymology: 1375–1425; late ME filtre < ML filtrum felt, piece of felt used to strain liquids < Gmc; see felt II fil′ter•er, n.