There’s an article in the newest Baum Bugle, which isn’t yet available in physical form, about the magic word from The Magic of Oz, discussed in the context of magic words in the series and other fiction. The writer, Dennis Wilson Wise, distinguishes it from simple nonsense words and the concept of true names. He also contrasts it with magic spells, like the one the Nome King uses to transform the Shaggy Man in Tik-Tok, which is almost a palindrome and includes ascending and descending vowels. In terms of individual words, Land gives us “Yeowa!” as the last word of a longer incantation Mombi uses.
More common are spells made up of words set in patterns, often rhyming or consonance.
There’s “weaugh, teaugh, peaugh” in Land, which activates the Powder of Life (although it works just fine without the words in Road and Patchwork Girl); and the incantation to summon the Winged Monkeys in Wizard.
In both of these cases, the words are accompanied by motions and a magical item. Rhyming often seems to be a key part of magic, both in Oz and in many other fairy tales. Polychrome‘s spells in Tin Woodman to repair Nick Chopper and Captain Fyter are in English verse. The same goes for the Wizard of Oz turning handkerchiefs into tents in Emerald City and commanding his magic axe in Magic, as well as Shaggy summoning Johnny Dooit in Road. Ruth Plumly Thompson’s books made use of verses in nursery rhyme style, containing both English words and silly made-up ones, like the Mudge transportation rhyme in Cowardly Lion and Wumbo the Wonder Worker‘s chants in Gnome King.
Mombi tries a spell of this sort in Lost King, although it doesn’t work. Do rhymes have inherent magical power in Oz? Is that just to make them easier to remember, or a form of patter (which would explain why a man who was a show magician for years before learning real magic is so fond of it)? I will say that Oz isn’t that big on magic depending on belief or willpower; it usually just does what it does no matter who employs it and whether they know what it is. It might be worth noting, however, that the Nome King uses unidentified magic words to cast his enchantments with the Magic Belt, but once Dorothy takes it she can make it work with plain English.
And when the Nome temporarily regains the talisman in Gnome King and Pirates, he uses English (or Ozish, I guess) instead of magic words. Even in the case of PYRZQXGL, while the word is required to work a transformation, the details of the change can be given in the vernacular.
I also feel I should mention the magic formula from Lost King, “Two ought to be eaten before seven,” which apparently must be recited and acted out (meaning the caster has to eat two of something in front of seven others) in order for it to work.
The Bugle issue also contains a 1970 short story that I’d heard of several times but hadn’t yet read, Zenna Henderson’s “The Believing Child,” about a girl who finds out from her mother how the pronounce the word from Magic, and uses it to turn two bullies into rocks. Since her last name is Coven and her mom seems to recognize the word as magic (she wonders why they’d print something so dangerous in a children’s book), witchcraft might run in their family. The story is narrated by the girl’s teacher, who discusses how hard it is for the girl, Dismey, to fit in at school, and how she firmly believes all the fiction she hears. I guess it’s up to the reader whether the tale takes place in the same universe as the Oz books, or it’s Dismey’s own belief that makes the word work.