Source : Webster's Revised Unabridged Dictionary (1913)

Pipeclay \Pipe"clay`\, v. t.
   1. To whiten or clean with pipe clay, as a soldier's
      accouterments.

   2. To clear off; as, to pipeclay accounts. [Slang, Eng.]

Source : WordNet®

pipeclay
     n : fine white clay used in making tobacco pipes and pottery and
         in whitening leather [syn: {terra alba}]