Source : Webster's Revised Unabridged Dictionary (1913)

Piper \Pip"er\, n.
   1. (Mus.) One who plays on a pipe, or the like, esp. on a
      bagpipe. ``The hereditary piper and his sons.''
      --Macaulay.

   2. (Zo["o]l.)
      (a) A common European gurnard ({Trigla lyra}), having a
          large head, with prominent nasal projection, and with
          large, sharp, opercular spines.
      (b) A sea urchin ({Goniocidaris hystrix}) having very long
          spines, native of both the American and European
          coasts.

   {To pay the piper}, to bear the cost, expense, or trouble.