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.
Daniel Cassidy, in his book How The Irish Invented Slang, claimed that the American English slang term ‘booly dog’ for a policeman comes from Irish:
Buailteach (pron. búěl-t’aċ), adj., (someone) disposed or given to striking, whacking or beating; fig. a policeman. (Dineen, 134)
Even if buailteach sounded anything like booly dog, there would be a problem with Cassidy’s assumption that all languages readily slip between grammatical categories as easily as English. Cassidy assumed that an adjective can be used as a noun, that the adjective buailteach can be used to mean someone who hits. (He assumed the same thing about many other words, for example, that gaosmhar, an adjective meaning wise, can be used to mean a wise person.) In fact, Irish words tend to be more clearly marked than English words. In English, the noun house can be used as an adjective in phrases like ‘the house wine’. In Irish, this is fion an tí, the wine of the house. The word buailteach is not a noun and it has no figurative meaning of ‘policeman’.
Buailteach is pronounced something like boolchah. It sounds nothing like booly dog.
Finally, the consensus seems to be that booly dog has some connection with bullies or with bulldogs, which seems a reasonable conjecture to me.