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.

The word jazz may have come from a slang word jasm which meant? OK. Let's think. My stream of consciousness:
To answer the question, consider the following: 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. The answer is meaning spirit , energy , vigor.