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.
Loogin is a slang term in America for a fool. There is no agreement about its derivation. It may be from a surname like Logan.
According to Cassidy, it comes from the Irish leathdhuine. This word is not a bad match in terms of meaning but it is definitely a bad match in terms of pronunciation. However, don’t take my word for it. Listen to the sound files for leathdhuine at the link below to find the pronunciation in Connaught, Munster and Ulster Irish: