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.
One of Cassidy’s most idiotic and left-field claims is that giggle, meaning a half-suppressed laugh, comes from the ‘Irish’ gíog gheal.
Firstly, while the origins of giggle are unsure, certain facts are known. You can find some information on the origins of giggle here: https://www.etymonline.com/word/giggle and here: https://en.wiktionary.org/wiki/giggle
As for gíog gheal, Cassidy provides evidence for the existence of gíog and evidence for the existence of geal, but he provides no evidence that the two words have ever been combined in the Irish language. The phrase does not exist and in the absence of any evidence, there is no need for anyone to take Cassidy’s claim seriously.