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 word duds for clothes dates back a long way in English.
According to Douglas Harper, dudde was first found in English with the meaning of cloak around 1300. Then in the plural it was used for rags or clothes in general.
The late Daniel Cassidy, in his book of phoney etymologies, How The Irish Invented Slang, claims that duds comes from the ‘Irish’ do éadach, meaning your clothing, your clothes.
As any Irish speaker will tell you, the Irish for your clothes is do chuid éadaigh (literally ‘your part of cloth). Do éadach doesn’t exist and is therefore not the origin of duds. Even if it did exist, phrases involving words for ‘your’ or ‘my’ are hardly ever borrowed between languages. Individual words (especially nouns) in their most basic, singular, uninflected form tend to be borrowed, not random phrases like this.