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.
Cassidy claims that grouch comes from the Irish cráite (kraw-cha or krah-cha), which means tormented. This is not a good match in terms of sound or meaning.
Back in the real world, grouch is believed to be a version of the ancient word grutch: