I've been pootling through William Goldman's The Princess Bride and came across this line:
glamour is an ancient concept. See "glamer" in the Oxford English Dictionary.
Well... depends what you mean by ancient as glamer is merely eighteenth century. But the fun thing about glamour is that it's grammar.
The glamour of grammar is a bit easier to understand if you consider the French grimoire, meaning book of incantations and spells. Once upon a time, grammar meant any sort of writing or learning. Writing, to those who don't do it, is a mysterious business and so a book of spells and magical incantations became known as a grammar or, by slight French alteration, a grimoire (which has nothing to do with grim).
In Scotland such magical grammars started to be pronounced with a L instead of an R, and thus a Scottish word for a spell was a glamer, usually in the phrase to cast a glamer over. Glamer became glamour and was imported back into English English by Sir Walter Scott, usually in the phrase to throw a glamour on somebody.
And so by the late nineteenth century, our modern glamour had emerged.
So it's just the old L-R confusion. And, if you want to know how that works, watch the video below:
Requiescat In Pace