D defs.my
Entry 1 sense Webster, 1913

Cornet-à-piston

/(k?r"n?t-?-p?s"t?n; F. k?r`n?`?p?s`t?n")/ · Cor·net-à-pis·ton · IPA
01 n. A brass wind instrument, like the trumpet, furnished with valves moved by small pistons or sliding rods; a cornopean; a cornet.
pl. Cornets-à-piston
  1. 1.
    A brass wind instrument, like the trumpet, furnished with valves moved by small pistons or sliding rods; a cornopean; a cornet.(Mus.)