I'm wondering if there's a word to describe a phrase that swaps the first part of several words in a sentence, like 'leave no stone unturned' switching to 'no turn unstoned'.
I know a spoonerism is to switch the first letter of several words ('dats and cogs'), but is it still a spoonerism if you're switching more than one letter?
This is a spoonerism:
a transposition of usually initial sounds of two or more words (as in tons of soil for sons of toil)
You will note that, in the transformation of “no stone unturned” to “no turn unstoned,” only one syllable of “unturned” is swapped, and not the entire word, to produce a different, inappropriate word.
A more formal term from linquistics is metathesis:
transposition of two phonemes in a word (as in the development of crud from curd or the pronunciation \ˈpər-tē\ for pretty)
Although that particular definition says “in a word,” transposition of phonemes within phrases is also metathesis. For example, here is Encyclopedia Brittanica using the word metathesis for the Spanish el lagarto becoming the English word alligator, and the National Association of Science Writers using it to describe a napron becoming an apron.
These are not synonyms. A spoonerism is almost always done intentionally, for humor, and the sounds being exchanged are usually further apart. This gives us a play on words, such as a character who does this constantly, saying, “the queer old Dean,” and the audience figuring out that it was really the dear old Queen. More recently, the American comedy troupe “The Capitol Steps” had a routine like this called “Lirty Dies.”
Metathesis is usually a slip of the tongue that switches two sounds that are right next to each other. resulting in a new word.
More general terms, not used exclusively for phonemes, include transposition, rearrangement and permutation.
User Justin found two books that specifically refer to “no turn unstoned” or “no tern unstoned” as a spoonerism.
This is an anti-proverb [quotes from Wikipedia], or perverb:
the transformation of a standard proverb for humorous effect.
and
an allusive distortion, parody, misapplication, or unexpected contextualization of a recognized proverb, usually for comic or satiric effect.
Specifically, this seems to be formally classified as a "Permutation":
While keeping the syntactic structure, the words are jumbled: A waist is a terrible thing to mind.
It’s a malapropism :
the usually unintentionally humorous misuse or distortion of a word or phrase especially : the use of a word sounding somewhat like the one intended but ludicrously wrong in the context
If done intentionally as a pun, this would be called a transpositional pun. For example, in the context of paving a switchback trail with stones, someone might say "Leave no turn unstoned!" (sorry)
The Wikipedia page lists several more examples:
Dieting: A waist is a terrible thing to mind.
Olympic officials: The souls that time men's tries.
Hangovers: The wrath of grapes.
The oboe: An ill wind nobody blows good.
Feudalism: It's your count that votes!
Soldiers of fortune: Give chance a piece
Vigilantism: the soul of the Dark Knight
Trophies: the memory of persistence
Although not a standard term Rickism seems quite fitting:
When a person says a Rickism, he/she uses a figure of speech or an expression, where the essential point and meaning has been understood by the person using it, but the actual expression is said wrong because he/she never bothered to learn the actual expression- only when to use it — Urban Dictionary
