The buisine (Old French; also, busine, buysine, buzine) was a type of straight medieval trumpet usually made of metal, also called a herald's trumpet. It had a very long and slender body, usually one to two metres in length (some were reported to have been at least six feet in length) that tapered toward the end into a slightly flared bell. It is commonly seen in paintings being played by angels and often also bearing the banner of a nobleman. The term descends from Buccina, a Roman military horn.
The term is first found in the c1100 Chanson de Roland, and it was probably a general term for horns and trumpets rather than referring to a specific instrument. Early trumpets were slightly curved, but the term was applied c1300 to straight trumpets imported from the Middle East during the Crusades.
The modern German word for trombone, Posaune, is a corruption of buisine by way of busaun.