For some time now, some of my on-line friends have advised me to provide a version of CassidySlangScam without the invective aimed at Cassidy and his supporters. In response to that advice, I am working on providing a glossary of the terms in Cassidy’s ludicrous book How The Irish Invented Slang with a short, simple and business-like explanation of why Cassidy’s version is wrong.
Most people would assume that shindy is a variant of shindig and that they are of the same origin. Daniel Cassidy, in his etymological hoax, How The Irish Invented Slang, claimed that shindig derives from seinnt-theach, which he claimed means a house of playing music (it doesn’t), while the word shindy derives from seinnte, which means played. There is no reason why an adjective or past participle like seinnte would become a noun for a party. The claim is highly unlikely and seinnte (shen-cha) does not sound like shindy.