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.
A shanty is a term for a rough cabin. It was first used in the 1820s and derives from the Canadian French chantier, a lumberjack’s headquarters. The term Shanty Irish for the poor Irish underclass in the US is from a 1928 book by Jim Tully.
It has often been claimed that this word derives from the Irish seanteach or seantigh. Cassidy writes this sean tí, which is ungrammatical and incorrect. In spite of the similarity between seantigh and shanty, it is highly unlikely that the Irish word is the origin of shanty, for the simple reason that sean- means old. By their very nature, such shacks are new structures, not old houses, which is the meaning of seanteach or seantigh.
In any case, this is an old piece of folk-etymology in Ireland and has been in the public domain for more than seventy years.