1903, named for U.S. bandleader and composer John Philip Sousa (1854-1932).
The first sousaphone was made by C.G. Conn in 1899 expressly for Sousa's band and its bell opened directly upward. The present bell-front type was first made in 1908. ["International Cyclopedia of Music," 1939]
sourdough
sourly
sourness
sourpuss
sous chef
sousaphone
souse
soused
soutane
souteneur
souter