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.
The late Daniel Cassidy, in his book, How The Irish Invented Slang, claims that the English slang terms goof and goofy derive from Irish gáifeach, which according to Cassidy means ‘exaggerated, given to wild exaggeration, flamboyant, ostentatious, loud, loud-mouthed, querulous.’ This is pronounced guy-fah or gaw-fah depending on the dialect. It is an adjective. There is no noun gáif (the adjective comes originally from gábh, which means danger), so it is hard to explain where the basic word goof would come from if Cassidy were right (which he isn’t).
According to the most reliable Irish dictionary, Ó Dónaill, gáifeach is defined as ‘1a dangerous, terrible 1b (of sound) wild, loud, fierce 2a exaggerated, sensational, given to exaggeration 2b flamboyant, ostentatious’.
None of which really fit the bill of what goofy means, which is ‘foolish or harmlessly eccentric.’ Meanwhile, back in the real world, goof comes from an English dialect term goff, which in turn comes from the Middle French goffe meaning awkward or stupid.