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.
Ballyrag or bullyrag is an American term dating back to the late 18th century. There is no certainty about its origin, though it is probably linked to bully or to rag, both of which carry the meaning of verbal attack. There is an interesting discussion of its possible links on the OED blog here:
Cassidy claims that it comes from the Irish word bollaireacht. The link with bollaireacht is very improbable. For one thing, the –cht ending sounds nothing like a g, so the sound similarity is unconvincing. Secondly, the meaning of bullyrag (or bullyrag) is very specific. It means to harangue, browbeat or verbally bully someone. Bollaireacht is an obscure word meaning boasting. Boasting to someone and bullying them are completely different behaviours and there seems no reason to suppose that there is any connection between these two words.