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.
In his etymological hoax, How The Irish Invented Slang, Daniel Cassidy claimed that the word Ninny, meaning a fool, comes from the Irish naoidheanach, a variant of the word naíonda, meaning infantile or childish. In fact, words related to the word naíonán (child, infant) tend to be positive, not negative, so there is no record of naíonán being used to mean a fool.
Furthermore, naoidheanach (modern naíonda) doesn’t sound much like ninny (the vowel is long, for a start). Also, it is generally accepted that ninny is a shortened version of the English word innocent (aN INNocent), which was used as a noun for a simple person in 16th century English.