Cor"net-a-pis`ton (k?r"n?t-?-p?s"t?n; F. k?r`n?`?p?s`t?n"), n.; pl. Cornets-a-piston. [F.] Mus.
A brass wind instrument, like the trumpet, furnished with valves moved by small pistons or sliding rods; a cornopean; a cornet.
© Webster 1913.