For reasons we won't delve too deeply into, this is also the name of a popular music style in the
Star Wars universe. The (in)famous
Cantina Band in
Episode IV is, in fact, playing jizz, and according to various sources (
Tales from the Mos Eisley Cantina, etc.) they are
renowned amongst fans of the genre as masters of jizz.
The derivation of jazz is obvious; however, we may never know why the word was modified in that particular way. Mr. Lucas?