A layer of gravel, sand, or other material through which liquid is passed in order to remove impurities; also, a pond or tank containing such a layer.

(signal processing) A linear filter used for image texture analysis.

(signal processing) A filter that adds a delayed version of a signal to itself, causing constructive and destructive interference.

(signal processing) A bandstop filter with a narrow stopband.

plural of filter bed

A very thick filter paper or a pad composed of several filter papers

A relatively thick, stiff filter paper / A similar card used to hold biological liquid samples

A state of intellectual isolation resulting from exposure to only highly personalized Internet content.

The movement or passage of a motorcycle between cars or other vehicles stopped, or moving slowly, in adjacent lanes of traffic.

(digital signal processing) An audio filter that discards lower frequencies while preserving higher ones.