Longest word in English

The longest word in English depends upon the definition of what constitutes an English word. English allows new words to be formed by construction; long words are coined; place names may be considered words; technical terms may be arbitrarily long. Length can be in terms of orthography and number of written letters or phonology and the number of phonemes.

Major dictionaries
The longest word in any of the major English language dictionaries is pneumonoultramicroscopicsilicovolcanoconiosis, a 45-letter word which refers to a lung disease contracted from the inhalation of very fine silica particles specifically from a volcano. Research has discovered that this word was originally a hoax. It 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 flocci&shy;nauci&shy;nihili&shy;pili&shy;fication 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;te&shy;macho&shy;se&shy;lacho&shy;galeo&shy;kranio&shy;leipsano&shy;drimhypo&shy;trimmato&shy;silphio&shy;parao&shy;melito&shy;katakechymeno&shy;kichlepikossypho&shy;phatto&shy;peristeralektryonop&shy;tekephallio&shy;kigklopeleiol&shy;agoiosiraio&shy;baphetraganop&shy;terygon,

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 was first used in a McDonald's Restaurant advertisement to describe the Big Mac sandwich.

Constructions
English is a language which 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): ending 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-arian (25): an advocate of opposition to disestablishment
 * antidisestablishmentarian-ism (28): the movement or ideology that opposes disestablishment

The use of additional suffixes could stretch the word to 'antidisestablishmentarianistically,' with 34 letters. Of course, the process need not stop there: prefixes like neo- and contra- can be added.

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&mdash;it is a kind of amphipod. However, this name, proposed by B. Dybowski, was invalidated by the International Code of Zoological Nomenclature.

Aequeosalinocalcalinoceraceoaluminosocupreovitriolic, 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. In British usage, 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. One example, with 1,185 letters, is a chemical term referring to the coat protein of a certain strain of tobacco mosaic virus.

The IUPAC nomenclature for organic chemical compounds is open-ended, giving rise to the 189,819-letter chemical name Methionylthreonylthreonyl...isoleucine, the shortened version of a protein also known as titin, or sometimes connectin, which is involved in striated muscle formation. Its empirical formula is C132983H211861N36149O40883S693.

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 Taumatawhakatangihangakoauauotamateaturipukakapikimaungahoronukupokaiwhenuakitanatahul (85 letters) which is a hill in New Zealand.

The longest place name in the United States (45 letters) is Chargoggagoggmanchauggagoggchaubunagungamaugg, a lake in Webster, Massachusetts. It means "Englishmen at Manchaug at the Fishing Place at the Boundary" 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 known to Americans 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 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 official geographical name in Australia is Mamungkukumpurangkuntjunya Hill. It 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.

It is questionable whether any of the above (with the exception of New­town­mount­kennedy) are properly considered English words, being derived from Maori, Nipmuck, Welsh, Aboriginal and Irish words respectively, or being a conjunction of individual English words.

Scrabble
The longest hypothetically legal Scrabble word in North American play is ethyl­enediamine­tetra­acetates (28 letters). It is the plural of a word found in Merriam-Webster's Collegiate Dictionary, 10th edition, which was the dictionary of reference in North American Scrabble play for words of at least 10 letters until June 16, 2003. Naturally, this word is 'legal' in name only, since it would not fit on the board. There are many 15-letter words; the highest-scoring word on a Scrabble board is one of benzoxycamphors (45), sesquioxidizing (42) or oxyphenbutazone (41). Because sesquioxidizing has the high-scoring Q and Z, it would score 62 × 27 = 1674 if played across an edge of the board with three triple word squares and two double letter squares involved, thus more than doubling the high score for English language Scrabble, 830, set by Micheal Cresta in 2006. Benzoxycamphors would score only 59 × 27 = 1593 while oxyphenbutazone would only score 54 × 27 = 1458. Sesquioxidizing is not found in Webster's dictionary, although the roots of the word, sesquioxide and oxidizing, are.

Words with certain characteristics of notable length

 * Strengths is the longest word in the English language containing only one vowel.
 * Scraunched and schmaltzed are the longest monosyllabic words in current usage.
 * 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.
 * The longest word with the vowels in order is abstemiously. It and facetiously are the only two English words with all five vowels and the semivowel y in order.

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, hypolimnion.
 * The longest International English words typable using only the top row of letters are proprietor, perpetuity, repertoire and typewriter. In American English the word teetertotter (the equivalent of what is known as a see-saw) is longer.
 * 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 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.

Humour
"Smiles" is humorously considered to be the longest word, as there is a mile between the two "s"es. However, by this reckoning "beleaguered" would be the longest, as it contains a league, which is about three miles.