air filter

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A filter for removing dust and other particles from a stream of air, typically used in the air intake of an internal combustion engine, the output of an air compressor, the supply duct of a forced-air furnace, etc.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a filter that removes dust from the air that passes through it