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.
Daniel Cassidy, in his book How The Irish Invented Slang, claimed that the word goon, meaning an idiot (and later, a muscle-bound henchman) derives from the Irish word guan, meaning ‘a fool’. There are several problems with this. Firstly, Cassidy states that the English word is ‘origin unknown’, while most dictionaries (including the OED) regard it as a contraction of an earlier word goonie or gooney, which is known since the 16th century and means a fool or a large bird like an albatross. This seems perfectly reasonable and I can see no reason to prefer an Irish derivation to this well-known English origin.
Secondly, guan is not a common word in Irish. It is not given at all in Ó Dónaill’s dictionary, and in Dinneen’s dictionary it is ascribed to Ó Neachtain’s manuscript dictionary of 1730. It is not found in the 7 million word Corpas na Gaeilge. The word guanach for silly or fanciful is certainly common and is given in all dictionaries but guan itself is not.