Yeah, although often it's when I'd write an idiom that is way too Muggle to be referenced by a pureblood so I modify it. Just the other day I was looking at a replacement for "the birds and the bees" with both wands ‘n holsters and the flitterbys and jobberknolls. I should probably start keeping track because I've done it a lot, but I'd have to go back and reread old chapters to remember what I did. I know I used "off the broom" to mean unbalanced or crazy.

 

A couple of idioms that come to mind:

Its not my cauldron - not my problem
His cauldron's boiling over - he's lost his mind
His wand is a bit on the short side - he's got a terrible personality (this ties to what JK has said about wand length, short wands reveal personality defects)
Riding a splintered broom - unpleasant task
In a swish - in a moment/shortly

There's probably also a lot of comparisons to the more sentient magical creatures, as you'd indicated regarding trolls. Other ones that come to mind might be hippogriffs (prideful and stubborn), sphinxes (clever or tricksy), giant (even dumber than a troll) etc.

So to combine with one that you mentioned, a magical insult might be "You hippogriff headed mugglefucker".

 

I used '17 sickles go further than a galleon' in an old story, for 'walk before you run', and I enjoyed that.

I've had 'your ball is as full as mine' in mind for a long time, as a divination reference for your guess is as good as mine, but one that muggleborns can have their eyebrow raise at.

I like Mordecai's better, but: grab the twig end, or riding the twig end, for the same meaning as his.

 

Oh...interesting. I hadn't thought of divination references!

Your leaves are muddled - you're doing the wrong thing/your guess is as good as mine
A blank palm - completely useless
His cards need shuffled - he's predictable

 

This is delightful. I’ve got a couple from my recent exploits in fanfiction:

He’s as crazy as a Cleansweep – A play on an infamous defect in some of the company’s brooms in the 1950s that inverted rider input under certain conditions – most famously to the detriment of the Irish seeker at the 1954 World Cup. Contemporary use is mostly restricted to professional quidditch players.

His wand’s too shiny. – Describes someone who tries too hard to hide something.

Don’t get your wand in a twist. – Same as the muggle expression.

Don’t try to sell me a gold cauldron. – Don’t take me for an idiot.

He tried to sell me a knut for a galleon. – He tried to rip me off.

He’s like a chicken hatching a dragon’s egg. – He’s in way over his head.

 

I love this kind of thing! I've spent way too much time trying to come up with clever magical phrases to use while writing, but quite a few have ended up rather clumsy.

I've definitely used kneazle amongst the pigeons, speaking of trolls (instead of speak of the devil, and as an aside using troll in this phrase is what's done in Scandinavian languages), to see someone through amortentia-smelling fumes (instead of rose-tinted glasses) and "with all the subtelty of a bludger" and "hippogriff in a china shop". I think I've used "seeing thestrals" as a phrase to mean that you're imagining things.

For swearwords, I've had "go fuck yourself with a broken crystal ball" to be the standard insult for your angsty teenager, and in a similar vein lots of jokes about getting splinters in bad places from vigorous use of one or both ends of a broomstick. Mugglefucker I've used as well, it ended up being a minor plotpoint rather than just a pun, same with lots of derivations from mudblood, like I imagine with the way Mrs Black's portrait keeps screaming filth and dirt and scum, these words could have an even more offensive meaning in the wizarding world.

 

"Burn the witch" — Uttered (with the same inflection as "I'll be damned") when someone does some surprisingly impressive magic

 

Fun thread! I’ve used a bunch in my fic, although Muggle-borns and some half-bloods still use standard idioms. I also make up wizarding idioms to avoid using Americanisms.

The ones I can remember off the top of my head:

• Get your wand polished (get laid)
• Alchemy (as opposed to sexual chemistry). E.g., “She’s pretty, I guess, but the alchemy’s not there”
• Flash in the cauldron
• Looking like something the Kneazle brought in
• He’s not the quickest broom in the shed (not very bright)

 

Some possibilities:

'Not the fastest wand on the draw' - slow-witted
'Hag Breath' - foul breath
'Hung Like a House Elf' - self-explanatory

And, of course, from the gold standard fic for wizarding slang, which hopefully needs no introduction:

'Azkabait'
'I'd stick my bludger so far up her quaffle...'
'She's smoking like Fiendfyre'

and so many more

 

How about a wizarding language similar to the smurf language?

In this case the words wizarding would replace adjectives and to wizard would replace verbs if the speaker is male, female speakers would use the word witching and to witch.

It's funny imagining Ron trying to teach Hermione and Harry to speak it, and them just utterly failing to use the words correctly.

 

I'm confused, smurfs as in the cartoon smurfs (your link doesn't lead to anything)?

I'm just struggling to imagine how you would communicate if all adjectives are replaced with "wizarding/witching" and all verbs with "to wizard/to witch" - and how your reader understands any of the dialogue?

 

Yes

Weird I just opened a picture on a page and linked it.

The thing about Smurfs is that they pretty much randomly replace any word with Smurf, but without any real consistentcy, which word is replaced, somehow they can still understand each other fine, but it's completely beyond normal people.
Here is the smurf wiki talking about it
https://smurfs.fandom.com/wiki/Smurf_(language)

Here's two examples from it

Spoiler: Examples

Obviously the first one is an exaggeration of the way they usually talk, it's usually clearer what they mean from context. Overall this nonsensical language quirk seems like something that could fit quite well in into Harry Potter.

 

I'm just not seeing how that works in Harry Potter, except maybe in a crack fic?

 

Harry Potter already has a tendency to put words like magical or wizarding in situations where theyre entirely unneccesary in a society that are wizards by nature, this would just be taking it a step further. The way its usually in the books it's muggles would refer to their history specifically as human histoy, their banks as human banks, their families as human families or their Exams as human exams. What I am proposing would be to just have the implication be that the usage of the word in those instances actually represents something else.

 

...no its not.

Its used like muggles would say "Black history" or "Swiss Bank".

 

Gringotts is called Wizard's bank.
Joke Shops are called wizarding Joke Shops
They refer to their version of GCSE as Ordinary Wizarding Levels and their vesion of A-levels as Nastily Exhausting Wizarding Test
Their Chess is called Wizard chess
Their law as Wizarding law.

All of that would make sense if they were talking to muggles, or talked about by third parties, but amongst wizards themselves the usage of the word wizard in the context they are used is entirely unnecessary.

 

First of all I'm pretty sure on a couple of those exams are actually from canon. And secondly, its because they recognise that they exist alongside a much larger culture, one which a lot of wizards have some level of interaction with, so their naming conventions have evolved to identify when they're talking about something specific to the wizarding world.

Going from "Ordinary Wizarding Levels" to "all adjectives could be replaced with wizarding, and all verbs with to wizard" is a crazy leap and personally sounds ludicrous to me. It'd work in a short crack fic, where your goal is be utterly bizarre and do things that make no sense. I can't see it working in any other context.