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Longest word in English

There are endless debates over what is the longest word in the English language, and these debates revolve around the terms of consideration. If scientific or technical terms are allowed wholesale, then there is a potential for words of indescribable length, particularly in regard to the naming of organic and biological compounds such as proteins, such as Methionylglutaminy...serine (q.v.).

Table of contents
1 Popular usage
2 A coined term
3 Other long words
4 Constructions
5 Technical terms
6 Place Names
7 Sesquipedalianism

Popular usage

Antidisestablishmentarianism (a movement opposed to the separation of church and state) at 28 letters is popularly believed to be the longest word. It is the "best-known".

A coined term

The word pneumonoultramicroscopicsilicovolcanoconiosis (defined as "a lung disease caused by the inhalation of very fine silica dust") is certainly the longest word ever to appear in a non-technical dictionary of English (Source: OED). This 45 letter word first appeared in the Oxford English Dictionary in 1936, and has also since appeared in the Webster's Third New International Dictionary (under the alternate spelling of -konioisis), the Random House Unabridged Dictionary and the Merriam-Webster's Collegiate Dictionary, to name but a few.

Critics have complained that this word is a technical term (specifically, a medical term), and hence not worthy of consideration as the "longest word in general usage".

There is yet another, more serious problem with the term, which is referred to by logologists as "p45", which is that the word is a hoax. In Word Ways: The Journal of Recreational Linguistics, in several separate articles (May 1985, pp. 95-96; November 1986, pp. 205-206; May 1987, p. 82), researchers discovered that the word was a neologism invented in 1935 by Everett M. Smith, president of the National Puzzler's League, as an example of a theoretical word that might one day enter use if trends in medical word coinage were to continue. Research into the body of medical literature prior to his usage in 1935 have never successfully shown that the word existed prior to his coinage.

Other long words

Everett Smith's prediction seems to have been proven true by the 207,000+ letter word cited by the Guinness Book of Records which allegedly represents the name for human mitochondrial DNA.

The longest word which appears in William Shakespeare's works is the 27 letter honorificabilitudinitatibus. This is arguably an English word, but only because he used it.

The well-known song-title from the movie Mary Poppins Supercalifragilisticexpialidocious with 34 letters does appear in several dictionaries, but only as a proper noun, and defined in reference to the song title. Hence it may well be dismissed as a "real" word.

The Guinness Book of Records in 1992 (and subsequent editions) declares the "longest real word" in the English language to be floccinaucinihilipilification at 29 letters. Defined as the act of estimating as worthless, its usage has been recorded as far back as 1741. In recent times its usage has been recorded in the proceedings of the US Senate (Senator Jesse Helms used the word in 1999 during the debate on the Comprehensive Test Ban Treaty [Randolph V. Cinco]) and at the White House (by Press Secretary Mike McCurry in his December 6, 1995, White House Press Briefing).

The character Big Bird of Sesame Street sings the Latin alphabet, thinking it is a word. He reads Abcdefghijklmnopqrstuvwxyz aloud as "(ab-cud-ef-gï)(jek'l-m'nâp-kwûr)(stööv-wik-ziz)" and breaks into song.


It should be noted that 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. As an example, one of the longest words used in the Wikipedia is contraneoantidisestablishmentarianalistically at 45 letters (although there are reasons to believe this was somewhat contrived). The length of this word is enhanced by the use of "contra" and especially the suffix "-alistically" which can frequently be added to words ending in "-tion" (eg. nationalistically, traditionalistically, floccinaucinihilipilificationalistically).

The word nonetheless is an interesting study in just how complex a word can legitimately be assembled. This word can be analysed as follows:

It could be extended more by saying:

Of course, the original "disestablishment" can be broken down linguistically into simpler forms. It is first based on "establishment", or the bringing into being of something or the existence of that something. "Establishment" is then based on the verb "establish", to bring into being, or, literally, to make "stable" -- which is then the ultimate root.

Technical terms

The technical term for "Tobacco Mosaic Virus, Dahlemense Strain" is the current official longest word:


Another word, a scientific name for tryptophan synthetase, which is made up of 267 amino acids, has appeared written down a number of times and has 1,909 letters. According to the Guinness Book of World Records, 18th edition, it is the longest chemical word for C1289H2051N343O375S8:


Place Names

There is some debate as to whether or not a place name is a legitimate word. Without entering that debate, let it be noted that the longest officially recognized place name in an English-speaking country is Taumatawhakatang­ihangakoauauot­amateaturipukaka­pikimaunga­horonuku­pokaiwhenuak­itanatahu (85 letters) which is a hill in New Zealand.

The 58 letter name Llanfair­pwllgwyngyll­gogerychwyrndrobwll­llantysiliogogogoch is the famous name of a town in Wales in the United Kingdom. Critics, however, have alleged that the name (which was adopted in the mid 19th century) was contrived solely to be "the longest name of a town in Great Britain". The longest station name in the UK, at 68 letters, is: Gorsafawddacha'idraigodanheddogleddoll˘npenrhynareurdraethceredigion which was contrived to beat the Welsh Town.

The longest place name in the United States (45 letters) is Chargoggagogg­manchauggagogg­chaubunagungamaugg. The longest hyphenated name in the U.S. is Winchester-on-the-Severn, a town in Maryland.

It is questionable whether any of the above are English words, being Maori, Welsh, and native American words respectively.


Although only seventeen letters long "sesquipedalianism" deserves a mention. It is a made up word, derived from Latin, probably in the nineteenth century and was probably intended originally as a joke. It means literally "using words one and half feet long" ie eighteen inches (it would be inappropriate to convert this into the metric scale).

A word found from Hippopotomonstrosesquippedaliophobia - is the fear of long words (36 letters long). This too is a constructed word, with the "hippopotomonstro-" portion tacked on to give it additional length.

See also: English language, one-letter English word, two-letter English word