The Collaborative International Dictionary of English v.0.48:

Piper \Pi"per\, n. [L.]
   See Pepper.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. (Zool.)
      (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.
          [1913 Webster]

   To pay the piper, to bear the cost, expense, or trouble.
      [1913 Webster]

WordNet (r) 3.0 (2006):

piper
    n 1: someone who plays the bagpipe [syn: piper, bagpiper]
    2: type genus of the Piperaceae: large genus of chiefly climbing
       tropical shrubs [syn: Piper, genus Piper]