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 truth is probably quite simple. At some stage, racket as in to make a sound (especially used as a distraction for criminal activity) became linked to words like rack (to put someone on the rack) and rack-renting (to extort rent from someone) and thus a racket came to mean a criminal enterprise.
Cassidy claims that this is of Irish or Scottish Gaelic origin but gives a number of different terms in both languages with his chaotic and disorganised ‘system’ of referencing, where he gives all the references in a jumble at the end, so it is impossible to say with any certainty which of these terms Cassidy is claiming as the origin of racket or what evidence he has for this claim. For what it’s worth, here is Cassidy’s take on it:
Ragaireachd (pron. ragerǝċd), n., (Gaelic) violence; extortion, oppression, roguery Racaireacht (pron. rakerǝċt), n., dealing, selling. Ragair, n., an extortioner, a violent man, villain, rogue, deceiver; cf. reacaire, reacadóir, n., a seller, a dealer; an extortioner (Ó Dónaill, 988; Dineen [sic], 872 882; Dwelly 744.)
Of course, ragaireachd is Scottish Gaelic, not Irish, and it would be pronounced ragurrakhk, with a k sound at the end, not a d. There was very little if any Scottish Gaelic spoken in urban areas of the USA in the 19th century, so it and Ragair are probably not relevant, even if they do mean what Cassidy said. (Extortioner does seem to be one of the meanings of ragaire in Gaelic.) Even if these were relevant, they don’t sound much like racket or racketeer.
Racaireacht doesn’t exist. Reacaireacht means selling, reciting or gossiping, none of which are appropriate, and reacaire means seller, reciter or gossip. Ragaire is given in Dinneen as meaning an extortioner but the reference is to the 17th/18th century Kirk/Ó Broin Glossary (Egerton 158) which is a glossary of Scottish Gaelic terms.