As with many words that began in slang, there is no definitive etymology for jazz. However, the similarity in meaning of the earliest jazz citations to jasm, a now-obsolete slang term meaning spirit, energy, vigor and dated to 1860 in the Historical Dictionary of American Slang, suggests that jasm should be considered the leading candidate for the source of jazz. A link between the two words is particularly supported by the Daily Californian's February 18, 1916, article, which used the spelling jaz-m, although the context and other articles in the same newspaper from this period show that jazz was intended.
Scholars think Jasm derives from or is a variant of slang **** or gism, which the Historical Dictionary of American Slang dates to 1842 and defines as "spirit; energy; spunk." **** also means ***** or sperm, the meaning that predominates today, making **** a taboo word. Deepening the nexus among these words is the fact that "spunk" is also a slang term for *****, and that "spunk"—like ****/jasm—also means spirit, energy, or courage (for example: "She showed a lot of spunk"). In the 19th and early 20th centuries, however, **** was still used in polite contexts. ****, or its variant **** (which, however, is not attested in the Historical Dictionary of American Slang until 1941), has also been suggested as a direct source for jazz. A direct derivation from **** is phonologically unlikely. Jasm itself would be, according to this assumption, the intermediary form. (Compare the analogous relationship between the slang terms spasm "a sudden burst of energy", as in spasm band,[1] and spaz(z).)
