Words With All Five Vowels: The Shortest, the Orderly and the Backwards

Every one of A, E, I, O and U turns up in education, dialogue and sequoia, and a patient search of the game’s word list finds 2,460 playable words that do the same. That list is the one Find the Word uses: the public-domain ENABLE list minus an offensive-word blocklist, 172,446 words in all (how we check words has the details). Every count below is for that list rather than for English as a whole, and a word qualifies if it contains each of the five vowel letters at least once. Some of what turned up is predictable, such as the heavy presence of long Latinate words, but several results are more surprising: how short these words can be, how few keep the vowels in alphabetical order, and how rarely Y joins the set cleanly. The findings are grouped below by question, each with the evidence.

How short can an all-vowel word be?

1. No word of six letters or fewer qualifies. A five-letter word would have to be made entirely of vowels, and a six-letter word would need five vowels around a single consonant. The list has no such words, so the floor sits at seven letters.
2. Exactly three seven-letter words make it: eulogia, miaoued and sequoia. Only the last is likely to come to mind unprompted. Miaoued is the past tense of miaou, one of the list’s spellings of a cat’s call, which is the kind of entry covered in the real-or-fake word quiz.
3. Seventeen eight-letter words qualify. The everyday ones are dialogue, equation and euphoria, joined by jalousie (a louvred blind) and sequoias. The rest are rarer, technical or regional, including aboideau and aboiteau, both names for a dike fitted with a sluice gate.
4. The densest words are eight letters long. Aboideau, aboiteau and eulogiae each pack six vowel letters into eight, a higher proportion than any other word in the group.

The pattern in the table has a simple explanation. Longer words have more slots for vowels, and many of them are assembled from prefixes and suffixes that bring their own vowels with them. Of the 2,460 words, 515 end in -ion or -ions and 104 end in -ous, which is why the group feels so heavily Latin. The prefix and suffix worksheet shows how quickly those endings multiply a single root. The longest word in the set is the 25-letter immunoelectrophoretically, and the most vowel letters in any one of these words is eleven, reached by seven words: counterrevolutionaries, overintellectualization and its plural, and the de- and re- forms of institutionalization and their plurals. (The overall record, 13 vowel letters in ethylenediaminetetraacetate, belongs to a word with no U.)

Each vowel exactly once

Allowing vowels to repeat makes the task easy for long words, so a stricter test is more revealing: every one of A, E, I, O and U must appear exactly one time. This removes words such as eulogiae (two Es) and aboideau (two As), and it shrinks the group considerably.

1. 717 words pass the stricter test, a little under a third of the 2,460.
2. The shortest are the same three seven-letter words, since eulogia, miaoued and sequoia use each vowel once already. At eight letters the count falls from 17 to 14.
3. Nine letters is where familiar words arrive. Education, authorise, authorize, behaviour, cautioned, housemaid, inoculate, nefarious, pneumonia and tenacious all qualify. The presence of both authorise and authorize is a reminder that the list accepts variant spellings, a topic taken up in why English spelling is so weird.
4. The longest reach eighteen letters. Hydrometallurgists uses each vowel once across eighteen letters, followed by the 17-letter hydrometallurgist and countercyclically. No qualifying word has 16 letters, and 20 have 15, including unsportsmanlike, uncopyrightable and uncomplimentary. Several of them use Y to supply extra vowel sounds without repeating a vowel letter.
5. Some of them repeat no letter at all. 229 of the 717 are isograms, words in which no letter appears twice, from sequoia up to uncopyrightable; the guide to isograms has the full records.

Vowels in alphabetical order

The best-known curiosity in this area is facetious, whose vowels run A, E, I, O, U with no repeats and no others in between. It has a small number of relatives in the list, and the table below gives all of them.

1. Only six words meet the strict definition, and four of them end in -ious. The ending itself contributes I, O and U in the right order, so the task reduces to finding a start that supplies A and then E with no other vowels.
2. The two adverbs complete the full set. Abstemiously and facetiously add a Y after the U, so their vowels read A, E, I, O, U, Y in alphabetical order. No other word in the list does this.
3. A looser test finds 28 words. If other vowels may appear between the five, as long as A, E, I, O and U can be picked out in order, the list adds words such as adventitious, sacrilegious, autoecious, ultraserious and arteriovenous.

Vowels in reverse order

1. Two words have U, O, I, E, A as their exact vowel sequence: subcontinental and uncomplimentary. Both begin with a U prefix (sub-, un-), which puts the U first and lets the rest of the word run backwards through the vowels.
2. The looser test finds six. Allowing other vowels in between adds unnoticeable, immunohistochemical, pseudocholinesterase and its plural. Reverse order is rarer than forward order in this list (six against 28), probably in part because common endings such as -ious and -ous put I, O and U near the end of a word.

Which of these records are worth quoting

Most records on this page come from a word list that accepts rare and technical words, so we checked how many of the 2,460 words anyone actually meets. Using wordfreq, a public frequency list built from Wikipedia, subtitles, news, books and web text up to about 2021, we counted a word as everyday if it appears at least once per million words. Only 94 of the 2,460 do, under 4 per cent.

What surprised us is that the familiar examples are almost never the record holders. The everyday words with all five vowels are long and plain, and 26 of the 94 end in -ion or -ions. The short, neat examples that make good trivia are the rare ones. Our advice for anyone quoting a record is to name the list it comes from and to prefer the recognisable runner-up: “sequoia is one of the three shortest” is true and useful, while “eulogia is the shortest” is true and tells a reader very little. A frequency list is a quick way to tell the two apart, with one caution: it does not separate names and brands from words, so check any surprisingly common short entry before relying on it.

Adding Y

Y often stands for a vowel sound, so a natural extension is to require it as well. This page still counts only A, E, I, O and U as vowel letters; Y is simply added as a sixth letter the word must contain. The list has 247 words containing all of A, E, I, O, U and Y. The stricter version, where each of the six letters appears exactly once, leaves 73.

Among longer words with all six letters once each, the recognisable ones tend to be adverbs in -iously or adjectives in -ary: tenaciously, veraciously, nefariously and precariously on one side, exclusionary and delusionary on the other. Evolutionary looks as though it belongs, but its two Os rule it out. The contrast with the opposite extreme is striking: where these words need at least ten letters to fit A, E, I, O, U and Y once each, the words with no vowels manage with none at all.

Which starting letters have them

1. C leads with 273 words, followed by A (245), U (216), S (196) and E (176). U ranks so high because of the prefix un-, which accounts for 169 of its 216 words by adding a U in front of an already vowel-rich word.
2. Three letters have none: in this list, no playable word starting with X, Y or Z contains all five vowels.
3. W has exactly one: warehousing. K has six, and all are technical: keratinous, kilogausses and four forms of keratoconjunctivitis.
4. Q has 18, including questionable, questionnaire, quaternion and quatrefoil. That is more than J (14), which is unusual for Q; the guide to the hard letters Q, X, Z and J explains why Q normally trails.

In a sixty-second round of Find the Word, long all-vowel words are rarely the quickest entries to type, but they are worth knowing as a reserve. When a letter such as Q or J has run dry of short words, a single questionable or jailhouse still counts as a valid word, and the vowel pattern makes it easier to spell under pressure than it looks.