n. In mining, the operation of securing the shaft of a mine from the ingress of water by ramming in clay between the casing and the rock.n. In architecture, decorations by means of coffers or sunken panels.n. A special method of making a watertight brickwork lining for a mine shaft, each course being laid in rings, without headers, and the bricks of alternate rings being floated in grout, breaking joints horizontally with the other rings.