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.
This is a good example of how Cassidy manipulated and distorted the evidence to make his claims seem slightly more reasonable. In his book, How The Irish Invented Slang, Cassidy claimed that the English word mark derives from the Irish marc. As usual, there is no evidence for this and plenty of strong evidence against it.
For one thing, while the word marc is Irish and means a mark, the word is a relatively modern borrowing from English and there is no evidence of it meaning target of a scam. In Irish, the earliest references date back to 1639, in the Catechismus of Tiobóid Galldubh (Theobald Stapleton).
Cassidy lies about this, defining marc as ‘a target; a goal; (of person) a mark’. This definition is not found in any dictionary or text or other source. It is strange that Cassidy, a man who spoke no Irish at all, considered it perfectly acceptable to invent meanings for Irish words or rewrite the dictionary definitions and his habit of doing this essentially leaves his entire book worthless.
In English, the word mark is very ancient. It had acquired the meaning of target by the year 1200. It was first used with the meaning of target of a scam or sucker in the 1880s. Marc never acquired that meaning in the Irish language.