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.
Shonicker is an offensive term for a Jewish person. There are many theories but none of them are widely accepted.
Daniel Cassidy, in his work of etymological fiction, How The Irish Invented Slang, claimed that shonicker comes from the Irish word sionnach, meaning a fox. There is no reason to suppose that this is correct. It is based on nothing more than a random similarity of sound between the two languages and as sionnach is pronounced shunnah, even the similarity of pronunciation is not great.