filter

¹fil·ter

noun \ˈfil-tər\

Definition of FILTER

1

: a porous article or mass (as of paper or sand) through which a gas or liquid is passed to separate out matter in suspension

2

: an apparatus containing a filter medium

3

a : a device or material for suppressing or minimizing waves or oscillations of certain frequencies (as of electricity, light, or sound) b : a transparent material (as colored glass) that absorbs light of certain wavelengths or colors selectively and is used for modifying light that reaches a sensitized photographic material—called also color filter