1. Type of medium weight cotton canvas cloth, specifically used for backdrops and covering flats. Heavier, but more durable than muslin. Also known as Duck Cloth, this durable, 7 oz. closely woven 100% cotton fabric comes in a contemporary range of colors. 2. Audio. To attenuate one source to allow another prominence. A "ducking circuit" or "ducker" is often used to lower the background music when an announcement is made, for example. From http://www.rane.com/par-d.html: 3. A slang term to "Get your head down or have it taken off."