Liczba mnoga: fipples

ETYM perh. from Latin fibula a clasp, a pin; cf. Prov. Eng. fible a stick used to stir pottage.
A wooden plug forming a flue pipe (as the mouthpiece of a recorder).
Plug in the mouthpiece of a wind instrument.

Liczba mnoga: fipple flutes

A woodwind with a vertical pipe and 8 finger holes and a whistle mouthpiece; SYN. fipple pipe, recorder, vertical flute.
Term describing a whistle, such as the Baroque recorder, that has a plug or “fipple” inserted into the mouthpiece to direct the flow of air precisely at the airfoil.