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.
Puss (not the cat, which is of Dutch origin) but in expressions like a slap in the puss or a sourpuss comes from the Irish expression pus which means a pout or a pouting mouth. This is a phonological variant of an earlier word bus, meaning a lip. In general, no native Irish words begin with the letter p. Cassidy says that a few Anglo-American dictionaries derive puss from the Irish word pus. This is a lie. ALL of them derive it from the Irish pus and did so long before Cassidy came along with his fake etymologies.