An Etymological Dictionary of the German Language/Posaune
Posaune, f., ‘trumpet, trombone’; a loan-word, as is indicated by the accent; it is met even during the MidHG. period as busûne, basûne, bosûne. On account of the remarkable variant busîne the word has been derived from OFr. buisine, which, like Ital. búccina, ‘trumpet,’ is based on Lat. bûcī̆na. Comp. further Du. bazuin, ‘trumpet.’