(n.) in wordplay, a pattern in which a series of words can be spelled with all five vowels in rotation
Word sets like pat, pet, pit, pot and put, that differ only in a single vowel, are popularly known as ‘vowel movements’.
That’s a term first introduced in 1998 by the American author and linguist Richard Lederer (better known online as wordplay and language expert Verbivore). Before then, sets of words like these were known somewhat less imaginatively as ‘vowel rotations’, given that each word is respelled by each vowel in rotation. Under that guise, they have been discussed in wordplay and recreational linguistics communities since the mid 1960s, when the author Dmitri Borgmann first posed this curious problem:
Five common English words with an obvious letter relationship are LAST, LEST, LIST, LOST and LUST. Unfortunately, modern English does not include a word LYST. Can you, perchance, find a group of six such words, all of which belong to modern English?
Word Ways (August 1968)
If you wish to count Y as a vowel, then you can up these lists to six entries with the likes of Dane, dene, dine, done, dune and dyne (a unit of force equal to 0.00001 newtons), and math, meth, mith, moth, muth and myth (mithing, or meithing, being an old word for navigating using landmarks, and muth being both an old word for a Hindu temple, and dialect word for an unspecified large quantity). But both those extended lists have to bend the rules slightly: Dane is a proper noun, and few people talk of muths or utilise dynes and mithing, except for wordplay experts looking around the dustier corners of the dictionary for words like muth and mith.
The same rule-bending has to be called upon if we want to try to extend the length of these vowel movements past four letters too. Although we listed a few 7-letter examples of vowel movements over on Twitter (like blander, blender, blinder, blonder and blunder), there are longer sets of words available here, so long as you allow a little room for imagination.
Blathering, blethering, blithering, blothering and bluthering, for instance, is a 10-letter vowel movement—so long as you’re happy to accept four versions of essentially the same word (blather, blether, blither and blother all mean to talk nonsense or gabble), plus a fairly obscure dialect word, bluther, meaning ‘to smudge wet ink’. Similarly, you can add slathering, slethering, slithering, slothering and sluthering to this list—but only if you’re okay with slether being a dialect version of slither, and both slother and sluther essentially being equivalents of one another (that is, obscure dialect words meaning to drag the feet, or loiter around).
You could even argue that these all these –ing verb forms could be made into gerund nouns if you wanted to take all this a step further. So say you were comparing two or more different methods of slathering, slethering, slithering, slothering and sluthering, you could find yourself talking about slatherings and slutherings—which would up all of these words to 11 letters. But admittedly, we’re so linguistically off piste here already that this is perhaps one vowel movement too far.