- "Over the murmur of the river he could make out more voices, but they were not speaking English or any human language he had ever heard. It was a rough and unmelodious tongue, a string of rattling, guttural noises..."
- —Harry Potter overhears Griphook and Gornuk converse in Gobbledegook.[src]
Gobbledegook is the native language of the goblins. It has been described as a harsh, rasping language, which makes it sound distinctly inhuman. It is able to be spoken by non-goblins; Barty Crouch Snr, Dirk Cresswell, and Albus Dumbledore were known to speak the language. Gobbledegook is one of the seventy-two languages in which Miranda Goshawk's Book of Spells was published in.
In the Three Broomsticks Inn, it is spoken by two goblins defrauded by Ludovic Bagman in 1995. In 1997 when Harry Potter, Hermione Granger, and Ronald Weasley overhear fellow fugitives Dirk Cresswell and the Goblins Gornuk and Griphook converse in Gobbledegook, while they were on the run from the Snatchers.
- Bladvak means "pickaxe" in Gobbledegook, according to Ludovic Bagman.
Gobbledygook, or Gibberish, are synonyms of the word "nonsense". It's likely that wizards started calling the language Gobbledegook, because it sounded unlike any language they knew and seemed just gibberish in their ears. It's possible or even likely, that Gobbledegook language is referred to with an completely different word in Gobbledegook.
Of course, there is also the possibility that Gobbledegook is called just that (or some close phonetical approximation) in the language. The similarity of the words "goblin" and "gobbledegook" should not be dismissed out of hand. If this is the case, it is not too hard to imagine how it might have made its way into muggle language through some muggleborns accidentally letting the word slip when they went back home for vacation.
- Harry Potter and the Goblet of Fire (First appearance)
- Harry Potter and the Deathly Hallows
- Wonderbook: Book of Spells (Mentioned only)