Search results for 'filter':

filter noun 1 a porous substance that allows liquid, gas, smoke, etc through, but traps solid matter, impurities, etc. 2 a device containing this. 3 a fibrous pad at the unlit end of a cigarette, and some types of cigars, that traps some of the smoke's impurities, such as tar. 4 a transparent tinted disc used to reduce the strength of certain colour frequencies in the light entering a camera or emitted by a lamp. 5 elec, radio a device for suppressing the waves of unwanted frequencies. 6 Brit a traffic signal at traffic lights that allows vehicles going in some directions to proceed while others are stopped • The pedestrian failed to notice the filter for traffic turning left. verb (filtered, filtering) 1 tr & intr to pass something through a filter, often to remove impurities, particles, etc. 2 intrans to go past little by little. 3 intrans, Brit said of vehicles: to proceed with one of the streams of traffic at a filter. See also filtrate.
ETYMOLOGY: 16c as filtre: from Latin filtrum felt used as a filter.