The Collaborative International Dictionary of English v.0.48:

Pug \Pug\, v. t. [imp. & p. p. Pugged; p. pr. & vb. n.
   Pugging.] [Cf. G. pucken to thump. beat.]
   [1913 Webster]
   1. To mix and stir when wet, as clay for bricks, pottery,
      etc.
      [1913 Webster]

   2. To fill or stop with clay by tamping; to fill in or spread
      with mortar, as a floor or partition, for the purpose of
      deadening sound. See Pugging, 2.
      [1913 Webster]