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.
Cassidy claims, without providing any evidence, that the gambling term Mark Anthony, apparently used as a version of the term mark meaning a target or a victim of professional gamblers, comes from the Irish marc andána, ‘a reckless mark’. There is no evidence of marc in Irish being used to mean a victim or target rather than a mark. The term andána does exist but is fairly obscure and is pronounced andahna or andawna. There is no evidence of the two words occurring together anywhere. They are not a recognised phrase and Cassidy had no authority for his claim that they constitute a meaningful phrase in Irish.
Of course, the most likely explanation for this English slang term is that it is English, that people began with the term mark and then added Anthony to it because the name Mark Anthony is well known. It should also be pointed out that it may have been influenced by a work of 19th century Irish fiction, The Fortunes of Hector O’Halloran and His Man Mark Anthony O’Toole, by W.H. Maxwell.