Source : Webster's Revised Unabridged Dictionary (1913)

Pibroch \Pi"broch\, n. [Gael. piobaireachd pipe music, fr.
   piobair a piper, fr. pioba pipe, bagpipe, from English. See
   {Pipe}, n.]
   A Highland air, suited to the particular passion which the
   musician would either excite or assuage; generally applied to
   those airs that are played on the bagpipe before the
   Highlanders when they go out to battle. --Jamieson.

Source : WordNet®

pibroch
     n : martial music with variations; to be played by bagpipes