I have just received an email from Ciara Ní Aodha, blogger, vlogger and tweeter (https://miseciara.wordpress.com/). She informs me that a comedy hip-hop duo from Limerick called the Rubber Bandits have tweeted with a number of Cassidy’s fake derivations.
Ciara, along with a few others like Eoin Ó Murchú and Liam Hogan, have warned readers of the Rubberbandits’ tweet about the accuracy of the material in it. She was also good enough to provide a link to my blog, so it seems appropriate to provide a quick run-down of the claims made with some real facts.
Slum, they say, comes from Irish ’s lom é, meaning ‘it’s bleak.’ Slum is first found in England, and meant a cheap room, so it’s probably from slumber. The idea that it comes from a phrase supposedly meaning ‘it’s bleak’ (it could just as easily mean ‘he’s naked’) is ridiculous.
Cop isn’t from Irish ‘ceap’. It comes from an English verb cop (of French origin) meaning to catch, as in cop on.
Racket supposedly comes from the Irish reacaireacht meaning to sell. You can find a discussion of its real origins here: http://www.etymonline.com/index.php?term=racket
You dig supposedly comes from Duigeann tú, Irish for ‘Do you understand?’ In reality, it’s spelled (An) dtuigeann tú? This is not proven, though it is possible and was first discussed in an article in 1981, long before Cassidy.
They claim that scam comes from s cam é, meaning trick or deception. There is, of course, no such word or phrase. It is a slightly odd (made-up) phrase meaning ‘it is crooked’. In fact, scam probably comes from escamotear, a Spanish word meaning to scam.
Scram probably comes from scramble. Scaraim doesn’t mean ‘I get away’ of course. It means I separate.
Uncle is probably from uncle. Anacal is an obscure Irish word for protection or quarter. It didn’t originate with Cassidy, anyway.
Buddy is almost certainly a childish corruption of brother.
Geezer is from guiser, an old word for a strange-looking person (originally disguiser). Gaosmhar is not a noun meaning wise person. It’s an adjective meaning wise.
Dude is an American term for a fop. It probably comes from the song Yankee-Doodle Dandy, where Doodle is associated with dandyism. (Apparently the term macaroni also meant a fop in the 18th century.) There is an obscure word dúid meaning many things including a shy and mopish person but this is probably just coincidental. There are several other claims for origins from languages like German too.
Gimmick probably comes from gimcrack. It isn’t from Irish camag because camag isn’t an Irish word. It’s Scottish Gaelic and it’s the equivalent of Irish camóg, as in camogie.
Loingseoir doesn’t mean a maritime worker. It means a pilot or sailor. The longshoremen aren’t sailors, they’re dockers. And longshoreman comes from the along shore men.
In other words, these claims are complete and utter bollocks. You can find further information on this blog and on other etymology blogs. It’s time people stopped spreading this lying nonsense and realised that Cassidy was a total fake who should be avoided by any sane and sensible human being.
cassidyslangscam 
I agree most if not all of your e.g.s are phoney, but it’s perhaps worth pointing out that some at least help to fix the Irish words in you mind by connecting them, however tenuously, with something that’s already meaningful. Also the game is endless 🙂
I wonder could ‘twig’ as in “have you twigged it yet” meaning ‘understand’ be related to _tuig_? Another Scots one you often see is ‘smashing!’ supposedly from _’s math sin_ “that’s good”. And of course ‘galore’ < _gu leòr_ …
Some, perhaps. If Cassidy had merely claimed to be creating mnemonics the little shit would be less hated here in Ireland but the fact is that in most of the cases the English slang terms connect to something like béal ónna or sách úr, which aren’t real Irish. Twig = tuig predates Cassidy by decades. It first occurs in Brewer’s, I think. Smashing from is maith sin is possible but you have to remember that smashing in English makes perfect sense as well – think of all the words like belter, a smash hit, bostin’, a thumping good film etc. which use the same metaphor. Galore is the same in Irish and Scottish Gaelic but there has never been any doubt that it is of Gaelic origin. All the dictionaries accept that. Hope you enjoy the blog! 🙂
GRMA! I guessed the ‘twig’ thing after you mentioned something a bit similar, I’d never seen it or thought of the connection before, although the G. word somehow ‘felt’ familiar.
béal ónna / sách úr : These terms are new to me, please explain?
BTW I know nothing of this ‘Cassidy’ of whom you speak, and TBH it’s probably best that way. Suffice to say there are many ‘cassidy’s’ in this world. Most of what people say about language is just hearsay, and when it comes to Celtic or indeed any little-know speech, you can usually guarantee total bollocks. OK if it’s just taken as a bit of fun, isn’t insulting etc. It’s only a danger when mistaken for ‘scholarship’ — LOL!
And that really is the danger here – things being taken for scholarship which aren’t even remotely scholarly. This blog is devoted to gutting and hanging out to dry the late Daniel Cassidy, author of How The Irish Invented Slang and inventor of most of the fake Irish derivations floating around. Have a read of the blog and you’ll soon understand that Cassidy was an ignorant, narcissistic fraud with no qualifications who managed to scam his way into a job in a private university as a professor. Unfortunately, however many people slam this garbage, there are still plenty of airheads out there who think that anything hated by large numbers of smart people must be correct … 🙂
Mar eolas, the link between twig (understand) and Irish tuig goes back to Walter Skeat, who died in 1912! As with all the supposed derivations that sound convincing, they were already out there long before Cassidy turned up.
As I write (3.59 on the 3rd of September, 2017), Galway and Waterford are drawn 10 points each. Na Déise abú!