Early 18th century (in an earlier sense). From German Posaune trumpet, trombone, organ reed stop resembling a trombone in tone from Old French busine, bosine, bousine.
Definition of posaune in US English:
posaune
nounpə(ʊ)ˈzaʊnə
Music
An organ reed stop resembling a trombone in tone.
Origin
Early 18th century (in an earlier sense). From German Posaune trumpet, trombone, organ reed stop resembling a trombone in tone from Old French busine, bosine, bousine.