Diplye
Dubious spelling in Marcuse, who erroneously considers this the main, correct spelling, dubiously referring to Baines (Woodwind), Grove and MGG, in which the spelling doesn't occur.
Marcuse, Sibyl: Musical instruments: a comprehensive dictionary. New York, 1975 (»Baines, Woodwind [?; ➺ Diple]; »Grove, 5th ed.; »MGG 1949 [?; NOT in MGG online!]).