In this section, "the five vowels" refers to a, e, i, o, u, and "the six vowels" refers to those letters plus the letter y.
A six-letter word with the five vowels in any order is AIOUEA (genus of plant in family Lauraceae) [Charles Turner].
Seven-letter words with the five vowels in any order are SEQUOIA, EULOGIA, EUNOIA (alertness of mind and will), MIAOUED, ADOULIE, EUCOSIA, EUNOMIA, EUTOPIA, MOINEAU, DOULEIA (an alternate spelling of DULIA which appears in W2), and EUODIAS (a name in Philippians 4:2). Allowing scientific names in biology, IOUEA is a genus of Cretaceous fossil sponges. BOIEAU is a town in Belgium. POAEUI Passage is in Papua New Guinea [Philip Bennett, Susan Thorpe, Stuart Kidd, Rex Gooch].
EUNOIA is the title of a book by Canadian poet Christian Bok which contains a series of univocalic prose poems. The first 20 or so poems use only the letter A, the next 20 use only E, and so on through I, O, and U. The book claims that eunoia means "beautiful thinking" and that it is shortest word using all five vowels. However, the word does not appear in English language dictionaries. Eunoia is the transliteration of a Greek word used by Aristotle and found in the New Testament which is translated "good will," or "benevolence," or "kindness." [Andreas Parsch, Philip Bennett, James A. Landau].
Eight-letter words with the five vowels in any order are AEQUORIN, AEROBIUM, AGOUTIES, DIALOGUE, EDACIOUS, EQUATION, EULOGIAS, EUPHORIA, EUSOCIAL, EXONUMIA, JALOUSIE, OUTRAISE, SAUTOIRE, SEQUOIAS, and THIOUREA [Philip Bennett, Charles Turner].
Each of the five vowels occurs in both words of the title AMOENITATUM EXOTICARUM, a book written and illustrated by Engelbert Kaempfer and published in 1690 [Charles Turner].
Eight-letter words containing the six vowels in any order are IALOUSYE, EURYOPIA, EYDOUXIA, EURYOMIA, EUMYOBIA, and JOYEUXIA [Stuart Kidd].
Nine-letter words containing the six vowels in any order are OXYURIDAE (pinworms), OXYGEUSIA (abnormal sensitivity to taste), LOUISELLA (a genus of fossil priapulid worm), and SEYMOURIA (genus of fossil amphibian). [Chris Cole, K. K. S. Bisht, Charles Turner].
Ten-letter words containing the six vowels in any order are ANEUPLOIDY, AUDIOMETRY, BUOYANCIES, AUTOTYPIES, COEQUALITY, EUKARYOTIC, and OXYURIASES [Philip Bennett, Stuart Kidd].
The shortest word with the five vowels in alphabetical order is AERIOUS (7 letters), meaning "airy." The OED2 shows one use of this word with this spelling in 1657. Other words with the five vowels occurring once each and in alphabetical order are: ABSTEINOUS, ABSTEMIOUS, ABSTENIOUS, ABSTENTIOUS, ACERIFLORUM, ACERIFLORUS, ACHEILOUS, ACHEIROUS, ACLEISTOUS, ADECTICOUS which is not in the OED2 but which web pages show is an adjective which describes a pupa with non-functional mandibles, ADVENTIOUS, AFFECTIOUS, ALEIKOUM, ALPESTRIOUS, ANEMIOUS, ANNELIDOUS, ARSENIOUS, ARTERIOSUM, ARTERIOSUS, ARTERIOUS, AVENIOUS, BACTERIOUS, CAESIOUS, CAMELIOUS, CARNELIOUS, FACETIOUS, FRACEDINOUS, GAREISOUN, GRAVEDINOUS, MAJESTIOUS, MATERIOUS, PARECIOUS, PLACENTIOUS, TRAGEDIOUS [Philip Bennett, Stuart Kidd, Paul Browning].
The longest word with the five vowels in alphabetical order is PHRAGELLIORHYNCHUS (a protozoan) [Susan Thorpe].
The shortest with the six vowels in alphabetical order is HAREIOUSLY (cruelly), which the OED2 shows in a single citation from a 15th-century manuscript [Susan Thorpe].
Pierre Abbat says ACEITOU (Portuguese for past tense of to accept) and ALEIJOU (Portuguese for past tense of paralyze) are the shortest words he knows in any language written in the Roman alphabet which have all five vowels in order.
The longest word containing all six vowels, with each vowel occurring only once, is ANTISTREPHORRHYNCHUS (an extinct crustacean) [Susan Thorpe]. Other long words are HYDROMETALLURGISTS and NONUNDERSTANDINGLY [Stuart Kidd]. The longest words containing the six vowels in alphabetical order, each occurring only once, are ABSTENTIOUSLY and MARVEILLOUSLY (variant of marvellously) [Susan Thorpe].
A species of louse, Haemodipsus lyriocephalus, has all the vowels once in each name [Stuart Kidd].
The longest words containing the five vowels in alphabetical order are SUPERCALIFRAGILISTICEXPIALIDOCIOUS (34) and PANCREATICODUODENOSTOMIES (25) [Stuart Kidd].
According to Philip Bennett, the longest words containing the six vowels in alphabetical order are PANCREATICODUODENOSTOMY and PANCREATICODUODENECTOMY (in the Merriam-Webster Medical Dictionary).
ULTRAREVOLUTIONARIES has each vowel exactly twice. The shortest such word is CUBOIDEONAVICULARE (Ligamentum cuboideonaviculare), and the longest, USSOLZEWIECHINOGAMMARUS (a small crustacean) [Susan Thorpe]. PSEUDOPSEUDOHYPOPARATHYROIDISM (which is in OED2) has each vowel at least twice.
OUENOUAOU (a stream in the Philippines) has vowels for 8 of its 9 letters and may be the longest place name with one consonant. PUNAAUIA (a village in Tahiti) has vowels for 6 of its 8 letters [Juozas Rimas]. OUABAIO (an African tree) has vowels for 6 of its 7 letters [Stuart Kidd]. OGOOUE (an African river) has vowels for 5 of its 6 letters.
SUOIDEA (the taxonomic group to which pigs belong) is the shortest word with the five vowels in reverse alphabetical order [Dmitri Borgmann]. The longest such word is PUNCTOSCHMIDTELLA (a crustacean) [Susan Thorpe, Stuart Kidd]. Other words with this property are DUOLITERAL, PRUNOIDEA (a suborder of radiolarian protozoa -OED), JULOIDEA, MUROIDEA (the mice-like rodent family), MUSCOIDEA (the family of two-winged flies), PULMONIFERA, RUDOIERA, SUBCONTINENTAL, SUBHYOIDEAN (beneath the hyoid bone), SUBPOPLITEAL, SUBVOICEBAND, QUODLIBETAL (of an issue that is presented for formal disputation), QUODLIBETARY (a quodlibetical argument), TUTOIERA, UNCOMPLIMENTARY, UNCONSIDERABLY, UNCONTINENTAL, UNCONVINCEABLY, UNNOTICEABLY, UNOBLITERABLY, UNOCCIDENTAL, UNORIENTAL, UNPOLICEMANLY, and UNPROPRIETARY [Philip C. Bennett, Charles Turner, Stuart Kidd, Paul Browning].
Words consisting entirely of vowels include AA (a type of lava), IAO, OII, EUOUAE, OO, I, O, A, and IO, which is an interjection in Chambers in addition to being one of the moons of Jupiter. All-vowel words in the OSPD3 are AA, AE, AI, EAU, OE. OO means "wool" (Scottish). The OED has the interjection AIEEE. AI is the three-toed sloth in Chambers and a Biblical place name and a Russian river. Other words consisting only of vowels are UOIAUAI (the name of a language in Par´ State, Brazil) [Dmitri Borgmann, in Charles Bombaugh's Oddities and Curiosities of Words and Literature, ed. Martin Gardner). The Samoan word UAEA means "wire" and is actually the English word spelled phonetically [Rémy Viredaz]. AIOUEA is a genus of the laurel famliy (Lauracea) [Charles Turner]. IOUEA is a genus of Cretaceous fossil sponges. The scientific name of the roseate spoonbill is AJAIA AJAIA (or AJAIA AJAJA); however, the J's would have been I's in the original Latin spelling, so that the words would consist entirely of vowels also.
Some all-vowel Hawaiian names for birds which are used in English are AO - Puffinus puffinus (Manx shearwater), UAU - Pterodroma phaeopygia (Dark-rumped Shearwater), OEOE - Oceanodroma castro (Harcourt's Storm-petrel), IO - Buteo solitarius (Hawaiian Hawk), OOAA - Moho bracatus, OU - Psittirostra psittacea.
Allowing proper nouns, some words consisting only of vowels include AIEA (a city in Hawaii), EIAO (one of the Marquesas Islands), EA (a town in the Basque section of Spain), AEAEA (the legendary home of Circe in the Tyrrhenian Sea), AAUAUA (a river in Brasil), II (a place in Finland 40 km north of Oulu), and OUEOI (an ancient Tuscan city in Etruria). IO is the only name on any hurricane name list which consists entirely of vowels. It is on the Central Pacific hurricane name list [Brett Brunner, Juozas Rimas, Stuart Kidd, Pertti Malo]. Dmitri Borgmann gives OEAEI (the name of the wife of Ra-amen, the spondist of Pthah) [An Archaic Dictionary, From the Egyptian, Assyrian, and Etruscan Monuments and Papyri, by William R. Cooper, London, 1876]. OUADI EL AOUAOUIYE is a location in Syria, AOUEOUA in Mauritania, and AOUEOUE in Togo [Rex Gooch].
Allowing Y as a vowel, some words consisting only of vowels include AYE, AYU, EYE, IYO, EYEY, and YAYA (although I am not sure which of these Y's are vowels!).
CWM (a glacial hollow on a hillside) has the rare W as a vowel, as does CRWTH (a type of stringed instrument). Both words are in MWCD10. They are pronounced "koom" and "krooth" (rhyming with room and truth). Other such words, not in MWCD10, are TWP (stupid), AWDL (an ode written in the strict alliterative meters), and LLWCHWR (a city-district in Wales). These words are of Welsh origin. The OED includes numerous archaic spellings in which W or V is a vowel.
Words containing no vowels include Q.T. (as in "on the q.t."), DJ, and RX, which MWCD10 classifies as words rather than abbreviations. (The reason apparently is that the letters are pronounced. Thus RV is an abbreviation when it stands for Revised Version, but it is a word when it means recreational vehicle.) A plural of RX is RXS, which has no vowels but three pronounced syllables.
Other words having no vowels are BRRR, GRR, HMMMM, JHVH, MR., MRS., MS, NTH, PFFT, pH, PHPHT, PHT, PSST, SH, SHH, SSSHHHHH, TSK, TSKS, TSKTSK, TSKTSKS, TV, YHWH, ZZZ, HSH (hush, W3), ST (silence, quiet, W3), TCH (vexation or disgust, W3), TCK (surprise or displeasure), and TST (hissed sound enjoining silence, W3). PHFFFT! and SSSSSSS are titles of movies from 1954 and 1973. The OED has TPRW (the sound of a horn). GRRL is in the Macquarie Dictionary, with the alternate spelling GRRRL [Charles Turner].
Note: In some of the following entries, the consonants l and r function as sonorants and thus fulfill the role of a vowel.
KRK is a Croatian island [Juozas Rimas].
Richard VLK of Pittsburgh profited from a vowelless last name in 1983 when he won over $20,000 by finding enough flip tops from Pepsi cans to spell his name 1,393 times.
William P. MLKVY played basketball for Temple University. He is referred to as the "Owl Without a Vowel," although the Y in his name is a vowel.
A banner held up at a baseball game read, "Hrbek, buy a vowel!" It referred to Kent HRBEK of the Minnesota Twins.
Strc prst skrz krk is Czech for "Put your finger through your throat." Stanislav Tvrdík supplied the longer sentence "Vlk prv strhl srst srn zhltl hrst zrn."
Bydd y cyllyll yn y cwpwrdd wrth y bwrdd (Welsh for "The knives will be in the cupboard by the table") does not use the vowels a, e, i, o, and u.
The longest common word without an A, E, I, O, or U is RHYTHMS, but these additional words appear in W2: SYMPHYSY, NYMPHLY, GYPSYRY, GYPSYFY. The OED2 has TWYNDYLLYNG(S). And WPPWRMWSTE (in the OED) goes nine letters without an A, E, I, O, or U; GLYCYRRHIZIN (a constituent of licorice) goes eight letters without A, E, I, O, or U. (In all these words, "Y" is a vowel.)
The longest word in dictionaries having only one vowel is STRENGTHS.
PSYCHORHYTHMS (W2) is the longest word with only one vowel, ignoring Y [Stuart Kidd].
Some long common German words with only one vowel are SCHRUMPFST (you shrink; 10 letters), SCHRUMPFT (he shrinks; 9 letters), SCHWIMMST (you swim, informal, 9 letters) SCHWIMMT (he/she/it swims 8 letters), STRUMPF (stocking, 7 letters) [Gerd Baron, Robbie Ellis].
Some long words with only one vowel which is allowed to repeat are: TATHAGATAGARBHA, TARAMASALATAS, HANDCRAFTSMAN, STRENGTHLESSNESSES, DEFENSELESSNESSES, EFFERVESCENCE, RETELEMETERED, DEGENERESCENCE, BEEKEEPER, and perhaps EYELETEERS, which is in OSW but I am unsure whether the Y is a vowel), INSTINCTIVISTIC, DISINHIBITING, KINNIKINNICKS, PHILISTINISMS, PRIMITIVISTIC, WHIPSTITCHING, MISSISSIPPI, LOXOLOPHODONTS, MONOPHTHONGS, POSTWORKSHOP, OCONOMOWOC (a town in Wisconsin), STRULDBRUGS, CURUCUCUS, DUMBSTRUCK, UNTRUTHFUL, NUMBSKULLS, MUNDUNGUS, USUFRUCT, SUSURRUS, SUCCUBUS, GLYCYLS, RHYTHMS. In addition CHRONONHOTONTHOLOGOS (in Roget’s Thesaurus, at "blusterer"), the title and hero of a 1734 burlesque tragedy by Henry Carey, is used for "anyone who delivers an inflated address" (Brewer's Phrase and Fable). In his book Language on Vacation, Dmitri Borgmann calls these words univocalics and lists SYMPHYSY as the longest Y-univocalic [Marc Broering, Dan Tilque, Stuart Kidd, Philip Bennett].
A word with six consecutive vowels is AIOUEA (a genus plant in family Lauraceae).
Words with six consecutive vowels include EUOUAE, which W2 defines as "A word formed from the vowels of seculorum amen, ending the Gloria Patri," AIOUEA (a genus of plants of the laurel family), and DIOOEAE (a tribe of cycads) [Charles Turner].
Words with five consecutive vowels include QUEUEING, the interjection AIEEE, which is in the OED, and COOEEING. (COOEE or COOEY, a peculiar cry of the Australian aborigine, is in W1, W2, and W3. The word is also a verb and both W1 and W2 show the forms COOEEING and COOEEYING.) The OED2 has COUUIENALES, which is a variant of quienals, which comes from quiennal, meaning "dispensation or indulgence for five years." Other such words are MIEAOU (OED) and MIAOUED and MIAOUING (what a cat does; OSPD and Webster's Collegiate Dictionary, 5th edition), ZAOUIA (an alternate spelling of zawiya according to the OED2 - Jeremy Marshall), JUSSIEUEAN ("pertaining to the natural system of botanical classification devised by Bernard de Jussieu and his nephew Antoine Laurent de Jussie" [W3]) and ZOOEAE (larvae of crabs and relatives [Chris Cole]) or ZOAEAE [OED]. The Kaula (Pteralyxia kauaiensis) and the Holei (Ochrosia kilaueaensis) are endangered Hawaiian plants, and the Formosan Sika (Cervus nippon taiouanus) is an endangered Taiwanese deer. MIOEUOTICUS is a primate genus. Cyclostremiscus beauii is a Marine snail from Florida [Charles Turner, Philip Bennett].
The entomologist A. A. Girault named a group of tiny wasps for writers, scientists, statesmen, and philosophers (Shakespearia, Beethovena, Goetheana, Marxella, etc.). He named a wasp genus THOREAUIA for Henry David Thoreau. This word has five consecutive vowels [Charles Turner].
Some words with four consecutive vowels follow (although in some of these words the Y may not actually be a vowel): aqueous, Archaeoastronomy, Archaeoindris fontoynonti (an extinct species of lemur), Aysheaia ( fossil onychophoran), ballyhooey, bayou, biyearly, buoyance, buoyancy, buoyant, buoyed, buoying, clayey, dequeue, dequeuing, employee, enqueue, eyeing, flooey, Gnaoua (a Moroccan ethnic minority group and part of the name of the Gnaoua & World Music Festival which is held annually in Essaouira, Morocco, which also has four consecutive vowels), gooey, guaiacum, Hawaiian, hooey, joyous, kayoed, kayoing, layout, layouts, maieutic, obloquious, obsequious, onomatopoeia, palaeoanthropic, palaeoanthropology, Paraguayan, payee, pharmacopoeia, prosopopoeia, Quaoar (a term in the creation mythology of the Tongva people and a Kuiper Belt object discovered in 2002), quayage, queue, radioautograph, reliquiae, royaux, Rubaiyat, Sequoia, subaqueous, terraqueous, Uruguayan, Vegavis iaai (Late Cretaceous bird from Antarctica), voodooienne, voyeur, Yaounde [Nelson H. F. Beebe, Charles Turner, Paul Wright].
Craig Rowland reports that in Quebec, there is a region known as the Outaouais, which, if in adjectival form, becomes lowercase, hence outaouais. The feminine form of this adjective is OUTAOUAISE, making it an eight-vowelled ten-letter word. He also says that in Quebecois French, the word for bullfrog is OUAOUARON, with six vowels in a row.
The Hawaiian word HOOIAIOIA (meaning "certified") has eight consecutive vowels and is listed in the 1976 Guinness Book of World Records [Charles Turner].
Allowing proper nouns, CAUAIAUAIA in Angola has nine vowels in a row, as does URU-EU-UAU-UAU (a language of Brazil with about 100 speakers in 1995; also spelled URUEWAWAU or ERU-EU-WAU-WAU), ignoring hyphens and OUADI EL AOUAOUIYE, in Syria [Susan Thorpe, Rex Gooch].
Allowing proper nouns, IJOUAOUOUENE, a mountain in Morocco, has 8 consecutive vowels as rendered by the French [Guinness]. Also with 8 consecutive vowels are the Bled El HAOUAOUIA area and OUAOUIOUST hill (both in Morocco), AGUINAOUIAOUI in Mali, and ISSOUOUAOUAR in Niger [Susan Thorpe]. In Estonian, ÕUEAIAÄÄR means "edge of a fence surrounding a yard" [Juozas Rimas, Ahto Truu].
OUAOUIATON appears on a French map of the central part of North America printed in 1693, and has 7 consecutive vowels. The word was later shortened to OUAOUIA, and was applied to the Indian tribe subsequently called Iowa. [The Book of Names, J. N. Hook.] Other place names with 7 vowels in a row include AOUEOUA, (Mauritania), AOUEOUE, Togo, BOUAAOUAM (Algeria), TIOUOOUORT (Mali), and ES ZOUAOUIINE and TAZOUOUOUARHT (Morocco) [Susan Thorpe, Rex Gooch].
OIOUEAE is one of the tropes or Gregorian formulas for the close of the lesser doxology in church music, representing the vowels in "World without end, Amen." [Music Lovers’ Encyclopedia (1954), by Rupert Hughes]
The ZOUAOUA are a Kabyli tribe living in Algeria and Morocco. UAIEUE (variants: UAIUAI, WAIWAI or OUAYEONE) is a language of Brazil indians. AAUAUA is a river in Brasil. These words have 6 consecutive vowels [Juozas Rimas]. Also with six consecutive vowels is INOEIOIO in Mozambique [Susan Thorpe].
In Dutch, KOEIEUIER (the udder of a cow) and PAPEGAAIEËIEREN (parrot eggs) have seven consecutive vowels, although they are no longer valid spellings, having been replaced by KOEIENUIER and PAPEGAAIENEIEREN [Joost Gestel, Tom Vernooij, John Slegers].
The Dutch word ZAAIUIEN (onions for seeding) has 6 consecutive vowels, still valid in the new spelling since 1995, although this is not found in the Van Dale dictionary [Oscar van Vlijmen].
HÄÄYÖAIE, a Finnish word for "a plan for the wedding night," has 7 consecutive vowels, and 6 of the 8 vowel sounds that exist in Finnish [Tapio Tallgren]. However, Juha Mäkinen writes, "There exists another variant of this word body which has 8 consecutive vowels called RIIUYÖAIE. It means 'a plan for the night before a companionship begins...' Both words are very easily understood by a native Finnish speaking person."
In Spanish, REHUÍAOS has all five vowels pronounced, as the "H" is silent. It is a form of the verb rehuir (to avoid) and means "I/he/she/it avoided you" [Ignacio Fernández Galván].
In Hungarian, fiaiéi ("those belonging to his/her sons") has five vowels (and five syllables) and only one consonant [Ádám Szegi].
Gary Rosenberg suggests that QUACKSALVER and QUICKSILVER may be the longest pair of words related by changing two identical vowels to a different set of identical vowels