Longest word in English
Updated: 12/20/2025, 1:14:19 PM Wikipedia source
The identity of the longest word in English depends on the definition of "word" and of length. Words may be derived naturally from the language's roots or formed by coinage and construction. Additionally, comparisons are complicated because place names may be considered words, technical terms may be arbitrarily long, and the addition of suffixes and prefixes may extend the length of words to create grammatically correct but unused or novel words. Different dictionaries include and omit different words. The length of a word may also be understood in multiple ways. Most commonly, length is based on orthography (conventional spelling rules) and counting the number of written letters. Alternate, but less common, approaches include phonology (the spoken language) and the number of phonemes (sounds).
Tables
mw- methionylthreonylthreonylglutaminylalanyl...isoleucine
mw- methionylthreonylthreonylglutaminylalanyl...isoleucine
Word
mw- methionylthreonylthreonylglutaminylalanyl...isoleucine
Letters
189,819
Meaning
The chemical composition of titin, the largest known protein
Claim
Longest known word overall by magnitudes. Attempts to say the entire word have taken two to three and a half hours.
Dispute
Technical; not in dictionary; whether this should actually be considered a word is disputed
methionylglutaminylarginyltyrosylglutamyl...serine
methionylglutaminylarginyltyrosylglutamyl...serine
Word
methionylglutaminylarginyltyrosylglutamyl...serine
Letters
1,909
Meaning
The chemical name of E. coli TrpA (P0A877)
Claim
Longest published word
Dispute
Technical
lopadotemachoselachogaleokranioleipsano...pterygon
lopadotemachoselachogaleokranioleipsano...pterygon
Word
lopadotemachoselachogaleokranioleipsano...pterygon
Letters
183
Meaning
A fictional dish of food
Claim
Longest word coined by a major author, the longest word ever to appear in literature
Dispute
Contrived nonce word; not in dictionary; Ancient Greek transliteration
pneumonoultramicroscopicsilicovolcanoconiosis
pneumonoultramicroscopicsilicovolcanoconiosis
Word
pneumonoultramicroscopicsilicovolcanoconiosis
Letters
45
Meaning
The disease silicosis
Claim
Longest word in a major dictionary
Dispute
Contrived coinage to make it the longest word; technical, but only mentioned and never actually used in communication
supercalifragilisticexpialidocious
supercalifragilisticexpialidocious
Word
supercalifragilisticexpialidocious
Letters
34
Meaning
Unclear – generally understood as a positive adjective or a nonsense word
Claim
Made popular in the Mary Poppins film and musical
Dispute
Contrived coinage
pseudopseudohypoparathyroidism
pseudopseudohypoparathyroidism
Word
pseudopseudohypoparathyroidism
Letters
30
Meaning
A hereditary medical disorder
Claim
Longest non-contrived word in a major dictionary
Dispute
Technical
antidisestablishmentarianism
antidisestablishmentarianism
Word
antidisestablishmentarianism
Letters
28
Meaning
The political position of opposing disestablishment
Claim
Longest non-contrived and nontechnical word
Dispute
Not all dictionaries accept it due to lack of usage.
honorificabilitudinitatibus
honorificabilitudinitatibus
Word
honorificabilitudinitatibus
Letters
27
Meaning
The state of being able to achieve honors
Claim
Longest word in Shakespeare's works; longest word in the English language featuring alternating consonants and vowels
Dispute
Latin
| Word | Letters | Meaning | Claim | Dispute |
| mw- methionylthreonylthreonylglutaminylalanyl...isoleucine | 189,819 | The chemical composition of titin, the largest known protein | Longest known word overall by magnitudes. Attempts to say the entire word have taken two to three and a half hours. | Technical; not in dictionary; whether this should actually be considered a word is disputed |
| methionylglutaminylarginyltyrosylglutamyl...serine | 1,909 | The chemical name of E. coli TrpA (P0A877) | Longest published word | Technical |
| lopadotemachoselachogaleokranioleipsano...pterygon | 183 | A fictional dish of food | Longest word coined by a major author, the longest word ever to appear in literature | Contrived nonce word; not in dictionary; Ancient Greek transliteration |
| pneumonoultramicroscopicsilicovolcanoconiosis | 45 | The disease silicosis | Longest word in a major dictionary | Contrived coinage to make it the longest word; technical, but only mentioned and never actually used in communication |
| supercalifragilisticexpialidocious | 34 | Unclear – generally understood as a positive adjective or a nonsense word | Made popular in the Mary Poppins film and musical | Contrived coinage |
| pseudopseudohypoparathyroidism | 30 | A hereditary medical disorder | Longest non-contrived word in a major dictionary | Technical |
| antidisestablishmentarianism | 28 | The political position of opposing disestablishment | Longest non-contrived and nontechnical word | Not all dictionaries accept it due to lack of usage. |
| honorificabilitudinitatibus | 27 | The state of being able to achieve honors | Longest word in Shakespeare's works; longest word in the English language featuring alternating consonants and vowels | Latin |
References
- YouTubehttps://www.youtube.com/watch?v=IZVbzNRUlQI
- CW39 Houstonhttps://web.archive.org/web/20200527051837/https://cw39.com/newsfix/worlds-longest-word-takes-3-5-hours-to-pronounce/
- A Student's Dictionary & Gazetteerhttps://archive.org/details/studentsdictiona00coli/page/524/mode/2up
- see separate article Lopado...pterygon
- Guinness book of world records: 1990https://archive.org/details/guinnessbookofwo00don_0e9
- Coined around 1935 to be the longest word; press reports on puzzle league members legitimized it somewhat. First appeare
- "Merriam Webster: Supercalifragilisticexpialidocious"https://www.merriam-webster.com/words-at-play/origin-supercalifragilisticexpialidocious
- "What is the longest English word?"https://web.archive.org/web/20081022192048/http://www.askoxford.com/asktheexperts/faq/aboutwords/longestword
- oxforddictionaries.comhttps://archive.today/20130131032923/http://www.oxforddictionaries.com/page/longestword?view=uk
- "Merriam Webster: "Antidisestablishmentarianism is not in the dictionary.""https://www.merriam-webster.com/words-at-play/no-antidisestablishmentarianism-is-not-in-the-dictionary
- "Cool, Strange, and Interesting Facts," fact 99. InnocentEnglish.com. Retrieved 2019-03-13.http://www.innocentenglish.com/cool-interesting-and-strange-facts/cool-strange-and-interesting-facts-page-3-3.html
- oxforddictionaries.comhttps://web.archive.org/web/20120719114141/http://oxforddictionaries.com/definition/english/pneumonoultramicroscopicsilicovolcanoconiosis#m_en_gb0642240
- Ask the Editorhttp://www.merriam-webster.com/video/0048-longest_word_in_dictionary.htm
- "Floccinaucinihilipilification" by Michael Quinion World Wide Words Archived 2006-08-21 at the Wayback Machine;http://www.worldwidewords.org/weirdwords/ww-flo2.htm
- The Guinness Book of Records, in its 1992 and previous editions, declared the longest real word in the English languagehttp://www.askoxford.com/asktheexperts/faq/aboutwords/longestword?view=uk
- In recent times its usage has been recorded in the proceedings of the United States Senate by Senator Robert Byrd Discus
- Eckler, R. Making the Alphabet Dance, p 252, 1996.
- "Longest Common Words – Modern"https://web.archive.org/web/20090427054251/http://www.maltron.com/words/words-longest-modern.html
- Sciencehttps://www.science.org/doi/full/10.1126/science.1161847
- Chemical Abstracts Formula Index, Jan.–June 1964, Page 967F; Chemical Abstracts 7th Coll. Formulas, C23H32-Z, 56–65, 196
- www.isthe.comhttp://www.isthe.com/chongo/tech/math/number/howhigh.html
- Opinions Rendered by the International Commission on Zoological Nomenclature: Opinions 105 to 114https://hdl.handle.net/10088%2F23619
- thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.comhttps://web.archive.org/web/20111117001007/http://www.thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.com/long428.html
- cited in some editions of the Guinness Book of Records as the longest word in English, see Askoxford.com on the longesthttps://web.archive.org/web/20011006121814/http://www.askoxford.com/asktheexperts/faq/aboutwords/longestword
- [1][dead link]http://perseus.uchicago.edu/hopper/morph.jsp?l=aequo&la=la
- The New York Timeshttps://www.nytimes.com/2004/11/20/national/20lake.html
- "Geoscience Australia Gazetteer"https://web.archive.org/web/20071001005330/http://www.ga.gov.au/bin/gazd01?rec=204304
- "South Australian State Gazetteer"https://web.archive.org/web/20071001000850/http://www.placenames.sa.gov.au/pno/pnores.phtml?recno=SA0078626
- "Guinness Records"http://www.guinnessworldrecords.com/world-records/longest-word-in-the-english-language-with-only-one-vowel/
- "Longest Word Without Repeating Letters"https://riddlesbrainteasers.com/longest-word-without-repeating-letters/
- "Typewriter Words"http://www.questrel.com/records.html#spelling_typewriter_order