Source : Webster's Revised Unabridged Dictionary (1913)

Fipple \Fip"ple\ (f[~e]r), n. [perh. fr. L. fibula a clasp, a
   pin; cf. Prov. E. fible a stick used to stir pottage.]
   A stopper, as in a wind instrument of music. [Obs.] --Bacon.

Source : WordNet®

fipple
     n : a wooden plug forming a flue pipe (as the mouthpiece of a
         recorder)