Pugging

n. [ See Pug, v. t. ] 1. The act or process of working and tempering clay to make it plastic and of uniform consistency, as for bricks, for pottery, etc. [ 1913 Webster ]

2. (Arch.) Mortar or the like, laid between the joists under the boards of a floor, or within a partition, to deaden sound; -- in the United States usually called deafening. [ 1913 Webster ]