jazz（n.）
到了1912年，美国英语中首次出现在棒球俚语中； 作为一种音乐类型，最早见于1915年。可能最终源自俚语 jasm （1860年）的“活力，精力，精神”，也许特指女性。这可能源自早期的 gism，意思相同（1842年）。
By the end of the 1800s, "gism" meant not only "vitality" but also "virility," leading to the word being used as slang for "semen." But — and this is significant — although a similar evolution happened to the word "jazz," which became slang for the act of sex, that did not happen until 1918 at the earliest. That is, the sexual connotation was not part of the origin of the word, but something added later. [Lewis Porter, "Where Did 'Jazz,' the Word, Come From?" http://wbgo.org Feb. 26, 2018]
到19世纪末，“gism”不仅意味着“活力”，还意味着“男子气概”，导致这个词被用作“精液”的俚语。但是，这是重要的是，尽管类似的演变也发生在“爵士”这个词上，它成为了性行为的俚语，但这至少要到1918年才发生。也就是说，性的涵义并不是这个词的起源，而是后来添加的。[刘易斯·波特，“‘爵士’这个词从哪里来？” http://wbgo.org，2018年2月26日]
“废话，不必要的谈话或装饰”的意思来自1918年。俚语 all that jazz “等等”首次记录于1939年。波特对研究的进一步观察如下：
"Jazz" seems to have originated among white Americans, and the earliest printed uses are in California baseball writing, where it means "lively, energetic." (The word still carries this meaning, as in "Let’s jazz this up!") The earliest known usage occurs on April 2, 1912, in an article discovered by researcher George A. Thompson, and sent to me courtesy of [Professor Gerald ] Cohen.
... By 1915, jazz was being applied to a new kind of music in Chicago. It seems to have been first applied to Tom Brown's all-white band, which hailed from New Orleans. This was followed by many printed references to jazz as a musical style.
“爵士”似乎起源于白人美国人，最早的印刷用法出现在加利福尼亚的棒球写作中，意思是“活泼，精力充沛”。（这个词仍然保留这个意思，比如“让我们来点爵士！”）最早的已知用法出现在1912年4月2日的一篇文章中，由研究员乔治·A·汤普森发现，并由[杰拉尔德]·科恩教授提供给我。
... 到了1915年，爵士开始被用来形容芝加哥的一种新音乐。它似乎首先被用来形容汤姆·布朗的全白乐队，该乐队来自新奥尔良。随后出现了许多关于爵士作为一种音乐风格的印刷引用。
该词起源时间：1912年