Plain English Meaning
Tiny reflective strips dropped from military aircraft to scatter radar signals, creating fake blips on radar screens.
Full Definition
Thin strips of metal foil, metallized film, or metal-coated fibers released into the air by military aircraft to reflect radar signals. Chaff produces clusters of false returns on radar displays, used to confuse or screen aircraft from radar tracking during training exercises or actual operations.
Context Anchor
Pilots may see chaff mentioned in FAA material, military activity notices, or radar and weather displays where a drifting return is not rain, snow, or an aircraft.
Derivation
From Old English 'ceaf,' meaning the husks of separated from the seed during threshing. The term borrows the image: , fluttering material scattered through the air, just as chaff drifts away from grain when winnowed.