One of the most ridiculous claims made by Daniel Cassidy is that the English word clamour derives from the Irish words glam mór. Glam means ‘bark, bay; howl, shout, roar’ and mór means ‘big’. This claim is made in several reviews of Cassidy’s book, such as this one: “The words and phrases of Ireland are as woven into the clamour (glam mor, great howl, shout and roar) … of American life as the hot jazz (teas, pron j’as, cd’as, heat, passion, excitement) of New Orleans.” However, it seems not to have made it to the book itself. Perhaps someone pointed out how ludicrous the claim was and Cassidy decided to surreptitiously bury it without comment. Several of Cassidy’s more gullible and deluded fans are still spreading it online.
And believe me, this claim really is total nonsense. Clamour (clamor in the American spelling) is on record in English since the Middle English period. It was used by Chaucer in the Canterbury Tales in 1385. Middle English took it from Old French and it ultimately derives from the Latin clamare, meaning to shout. It has cognates in Spanish and Portuguese. It has no connection with an Irish word for barking, except that an American nutcase who was completely barking thought it was Irish.