Longest word in English

The identity of the longest word in English depends upon the definition of what constitutes a word in the English language, as well as how length should be compared. In addition to words derived naturally from the language's roots (without any known intentional invention), English allows new words to be formed by coinage and construction; place names may be considered words; technical terms may be arbitrarily long. Length may be understood in terms of orthography and number of written letters, or (less commonly) phonology and the number of phonemes.

Major dictionaries
The longest word in any of the major English language dictionaries is pneumonoultramicroscopicsilicovolcanoconiosis, a word that refers to a lung disease contracted from the inhalation of very fine silica particles, specifically from a volcano; medically, it is the same as silicosis. The word was deliberately coined to be the longest word in English, and has since been used in a close approximation of its originally intended meaning, lending at least some degree of validity to its claim.

The Oxford English Dictionary contains pseudopseudohypoparathyroidism (30 letters).

The longest non-technical word in major dictionaries is flocci­nauci­nihili­pili­fication at 29 letters. Consisting of a series of Latin words meaning "nothing" and defined as "the act of estimating something as worthless"; its usage has been recorded as far back as 1741.

Coinages
In his play Assemblywomen (Ecclesiazousae), the ancient Greek comedic playwright Aristophanes created a word of 183 letters, which describes a dish by stringing together its ingredients: Lopado&shy;temakho&shy;selakho&shy;galeo&shy;kranio&shy;leipsano&shy;drim&shy;ypo&shy;trimmato&shy;silphio&shy;karabo&shy;melito&shy;katakekhy&shy;meno&shy;kikhl&shy;epi&shy;kossypho&shy;phatto&shy;perister&shy;alektryon&shy;opto&shy;kephallio&shy;kigklo&shy;peleio&shy;lagōio&shy;siraio&shy;baphē&shy;tragano&shy;pterýgōn.

Henry Carey's farce Chrononhotonthologos (1743) holds the opening line: "Aldiborontiphoscophornio! Where left you Chrononhotonthologos?"

James Joyce made up nine 101-letter words in his novel Finnegans Wake, the most famous of which is Bababadalgharaghtakamminarronnkonnbronntonnerronntuonnthunntrovarrhounawnskawntoohoohoordenenthurnuk. Appearing on the first page, it allegedly represents the symbolic thunderclap associated with the fall of Adam and Eve. As it appears nowhere else except in reference to this passage, it is generally not accepted as a real word. Sylvia Plath made mention of it in her semi-autobiographical novel The Bell Jar, when the protagonist was reading Finnegans Wake.

"Supercalifragilisticexpialidocious", the 34-letter title of a song from the movie Mary Poppins, does appear in several dictionaries, but only as a proper noun defined in reference to the song title. The attributed meaning is "a word that you say when you don't know what to say." The idea and invention of the word is credited to songwriters Robert and Richard Sherman.

Advertising coinages
In 1973, Pepsi's advertising agency Boase Massimi Pollitt used a 100-letter but several-word term "Lipsmackinthirstquenchinacetastinmotivatingoodbuzzincooltalkinhighwalkinfastlivinevergivincoolfizzin" in TV and film advertising.

In 1975, the 71-letter (but several-word) advertising jingle Twoallbeefpattiesspecialsaucelettucecheesepicklesonionsonasesameseedbun (read: two all-beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun) was first used in a McDonald's Restaurant advertisement to describe the Big Mac sandwich.

Constructions
The English language permits the legitimate extension of existing words to serve new purposes by the addition of prefixes and suffixes. This is sometimes referred to as agglutinative construction. This process can create arbitrarily long words: for example, the prefixes pseudo (false, spurious) and anti (against, opposed to) can be added as many times as desired. A word like anti-aircraft (pertaining to the defense against aircraft) is easily extended to anti-anti-aircraft (pertaining to counteracting the defense against aircraft, a legitimate concept) and can from there be prefixed with an endless stream of "anti-"s, each time creating a new level of counteraction. More familiarly, the addition of numerous "great"s to a relative, e.g. great-great-great-grandfather, can produce words of arbitrary length.

"Antidisestablishmentarianism" is the longest common example of a word formed by agglutinative construction, as follows (the numbers succeeding the word refer to the number of letters in the word):


 * establish (9): to set up, put in place, or institute (originally from the Latin stare, to stand)
 * dis-establish (12): to end the established status of a body, in particular a church, given such status by law, such as the Church of England
 * disestablish-ment (16): the separation of church and state (specifically in this context it is the political movement of the 1860s in Britain)
 * anti-disestablishment (20): opposition to disestablishment
 * antidisestablishment-ary (23): of or pertaining to opposition to disestablishment
 * antidisestablishmentari-an (25): an opponent of disestablishment
 * antidisestablishmentarian-ism (28): the movement or ideology that opposes disestablishment

Technical terms
A number of scientific naming schemes can be used to generate arbitrarily long words.

Gammaracanthuskytodermogammarus loricatobaicalensis is sometimes cited as the longest binomial name—it is a kind of amphipod. However, this name, proposed by B. Dybowski, was invalidated by the International Code of Zoological Nomenclature.

Aequeosalinocalcalinoceraceoaluminosocupreovitriolic, at 52 letters, describing the spa waters at Bath, England, is attributed to Dr. Edward Strother (1675–1737). The word is composed of the following elements:
 * Aequeo: equal (Latin, aequo )
 * Salino: containing salt (Latin, salinus)
 * Calcalino: calcium (Latin, calx)
 * Ceraceo: waxy (Latin, cera)
 * Aluminoso: alumina (Latin)
 * Cupreo: from "copper"
 * Vitriolic: resembling vitriol

John Horton Conway and Landon Curt Noll developed an open-ended system for naming powers of 10, in which one sexmilliaquingentsexagintillion, coming from the Latin name for 6560, is the name for 103(6560+1) = 1019683. Under the long number scale, it would be 106(6560) = 1039360.

Names of chemical compounds can be extremely long if written as one word, as is sometimes done. An example of this is sodiummetadiaminoparadioxyarsenobenzoemethylenesulphoxylate, an arsenic-containing drug. There are also other chemical naming systems, using numbers instead of "meta", "para" etc. as descriptive dividers, breaking up the name, which then no longer can be considered a single long word.

The IUPAC nomenclature for organic chemical compounds is open-ended, giving rise to the 189,819-letter chemical name Methionylthreonylthreonyl...isoleucine which is involved in striated muscle formation. Its empirical formula is C132983H211861N36149O40883S693. A 1,185-letter example, Acetylseryltyrosylseryliso...serine, refers to the coat protein of a certain strain of tobacco mosaic virus and was published by the American Chemical Society's Chemical Abstracts Service in 1964 and 1966. It marks the longest published word before in 1965, the Chemical Abstracts Service overhauled its naming system and started discouraging excessively long names.

The words Internationalization and localization are abbreviated "i18n" and "l10n", respectively, the embedded number representing the number of letters between the first and the last.

Place names
There is some debate as to whether a place name is a legitimate word.

The longest officially recognized place name in an English-speaking country is Taumatawhakatangihangakoauauotamateapokaiwhenuakitanatahu (85 letters), which is a hill in New Zealand. The name is in the Māori language.

In Canada, the longest place name is Dysart, Dudley, Harcourt, Guilford, Harburn, Bruton, Havelock, Eyre and Clyde, a township in Ontario, at 61 letters or 68 non-space characters.

The 58-character name Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch is the famous name of a town on Anglesey, an island of Wales. This place's name is actually 51 letters long, as certain character groups in Welsh are considered as one letter, for instance ll, ng and ch. It is generally agreed, however, that this invented name, adopted in the mid-19th century, was contrived solely to be the longest name of any town in Britain. The official name of the place is Llanfairpwllgwyngyll, commonly abbreviated to Llanfairpwll or the somewhat jocular Llanfair PG.

The longest place name in the United States (45 letters) is Chargoggagoggmanchauggagoggchaubunagungamaugg, a lake in Webster, Massachusetts. It means "Fishing Place at the Boundaries – Neutral Meeting Grounds" and is sometimes facetiously translated as "you fish your side of the water, I fish my side of the water, nobody fishes the middle". The lake is also known as Lake Webster. The longest hyphenated names in the U.S. are Winchester-on-the-Severn, a town in Maryland, and Washington-on-the-Brazos, a notable place in Texas history.

The longest official geographical name in Australia is Mamungkukumpurangkuntjunya Hill. It has 26 letters and is a Pitjantjatjara word meaning "where the Devil urinates".

In Ireland, the longest English placename at 22 letters is Muckanaghederdauhaulia (from the Irish language, Muiceanach Idir Dhá Sháile, meaning "pig-marsh between two saltwater inlets") in County Galway. If this is disallowed for being derived from Irish, or not a town, the longest at 19 letters is Newtownmountkennedy in County Wicklow.

Krung Thep Mahanakhon Amon Rattanakosin Mahinthara Yuthaya Mahadilok Phop Noppharat Ratchathani Burirom Udomratchaniwet Mahasathan Amon Piman Awatan Sathit Sakkathattiya Witsanukam Prasit is the ceremonial name of Bangkok, Thailand; it has the Guinness World record for longest place name in the world, not in English however.

Words with certain characteristics of notable length

 * Strengths is the longest word in the English language containing only one vowel.
 * Rhythms is the longest word in the English language containing none of the five recognised vowels.
 * Schmaltzed and strengthed appear to be the longest monosyllabic words recorded in OED; but if squirrelled is pronounced as one syllable only (as permitted in SOED for squirrel), it is the longest.
 * Euouae, a medieval musical term, is the longest English word consisting only of vowels, and the word with the most consecutive vowels. However, the "word" itself is simply a mnemonic consisting of the vowels to be sung in the phrase "seculorum Amen" at the end of the lesser doxology. (Although u was often used interchangeably with v, and the variant "Evovae" is occasionally used, the v in these cases would still be a vowel.)
 * The longest words with no repeated letters are dermatoglyphics, misconjugatedly and uncopyrightables.
 * The longest word whose letters are in alphabetical order is the eight-letter Aegilops, a grass genus. However, this is arguably both Latin and a proper noun. There are several six-letter English words with their letters in alphabetical order, including almost, biopsy, and chintz.
 * The longest words recorded in OED with each vowel only once, and in order, are abstemiously, affectiously, and tragediously (OED). Fracedinously and gravedinously (constructed from adjectives in OED) have thirteen letters; Gadspreciously, constructed from Gadsprecious (in OED), has fourteen letters. Facetiously is among the few other words directly attested in OED with single occurrences of all five vowels and the semivowel y.
 * The longest single palindromic word in English is rotavator, another name for a rotary tiller for breaking and aerating soil.

Typed words

 * The longest words typable with only the left hand using conventional hand placement on a QWERTY keyboard are tesseradecades, aftercataracts, and the more common but sometimes hyphenated sweaterdresses. Using the right hand alone, the longest word that can be typed is johnny-jump-up, or, excluding hyphens, monimolimnion. and phyllophyllin
 * The longest English word typable using only the top row of letters has 11 letters: rupturewort. Similar words with 10 letters include: pepperwort, perpetuity, proprietor, typewriter, requietory, repertoire, tripertite and pourriture. The word teetertotter (used in North American English) is longer at 12 letters, although it is usually spelled with a hyphen.
 * The longest words typable by alternating left and right hands are antiskepticism and leucocytozoans respectively.
 * On a Dvorak keyboard, the longest "left-handed" words are epopoeia, jipijapa, peekapoo, and quiaquia. Other such long words are papaya, Kikuyu, opaque, and upkeep. Kikuyu is typed entirely with the index finger, and so the longest one-fingered word on the Dvorak keyboard. There are no vowels on the right-hand side, and so the longest "right-handed" word is crwth.

Common words in general text
Ross Eckler has noted that most of the longest English words are not likely to occur in general text, meaning non-technical present-day text seen by casual readers, in which the author did not specifically intend to use an unusually long word. According to Eckler, the longest words likely to be encountered in general text are deinstitutionalization and counterrevolutionaries, with 22 letters each.

A computer study of over a million samples of normal English prose found that the longest word one is likely to encounter on an everyday basis is uncharacteristically, at 20 letters.

Humour
Smiles, according to an old riddle, may be considered the longest word in English, as there is a mile between the two s's. A retort asserts that beleaguered is longer still, since it contains a league. The riddle and both jocular answers date from the 19th century.

In the old time radio retrospective, Golden Radio, comedian Jack Benny jokes that "the longest word in the English language is the one that follows, 'Now, here's a word from our sponsor.'"