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.
According to Cassidy, this was a slang term for a fortified red wine and comes from the Irish fuad, an obscure word for a thief, a wretch or a vagrant. According to Corpas na Gaeilge, this was a common expression in the 17th century but is less common in modern Irish. I have never used it and I have never heard it used.
Of course, the real origin of the expression foot juice is pretty obvious. Everyone knows that people when they made wine according to the traditional method used to take their shoes and socks off and tread the grapes until the juice ran out. Isn’t this a much more likely origin for foot juice than an obscure Irish term which sounds a little like foot?