Longest word in English

The identity of the longest word in English depends on the definition of a 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).

Word Letters Meaning Claim Dispute
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[1] to three and a half hours.[2] 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[3] Technical
lopadotemachoselachogaleokranioleipsano...pterygon 183 A fictional dish of food Longest word coined by a major author,[4] the longest word ever to appear in literature[5] Contrived nonce word; not in dictionary; Ancient Greek transliteration
pneumonoultramicroscopicsilicovolcanoconiosis 45 The disease silicosis Longest word in a major dictionary[6] 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[7] Contrived coinage
pseudopseudohypoparathyroidism 30 A hereditary medical disorder Longest non-contrived word in a major dictionary[8] Technical
antidisestablishmentarianism 28 The political position of opposing disestablishment Longest non-contrived and nontechnical word[9] Not all dictionaries accept it due to lack of usage.[10]
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[11] Latin
  1. ^ "Reading The Longest English Word (190,000 Characters)". YouTube. 2 June 2017. Archived from the original on 2021-11-10. Retrieved 2 August 2020.
  2. ^ "World's longest word takes 3.5 hours to pronounce". CW39 Houston. 2012-12-08. Archived from the original on 2020-05-27. Retrieved 2020-05-18.
  3. ^ Moore, Colista (1 January 2006). A Student's Dictionary & Gazetteer (11th ed.). Sullivan's Island: The Dictionary Project. p. 524. ISBN 978-0-9771777-5-2.
  4. ^ see separate article Lopado...pterygon
  5. ^ Donald McFarlan; Norris Dewar McWhirter; David A. Boeh (1989). Guinness book of world records: 1990. Sterling. p. 129. ISBN 978-0-8069-5790-6.
  6. ^ Cite error: The named reference p45 was invoked but never defined (see the help page).
  7. ^ "Merriam Webster: Supercalifragilisticexpialidocious".
  8. ^ "What is the longest English word?". AskOxford. Archived from the original on 2008-10-22. Retrieved 2010-08-22.
  9. ^ "What is the longest English word?". oxforddictionaries.com. Archived from the original on January 31, 2013.
  10. ^ "Merriam Webster: "Antidisestablishmentarianism is not in the dictionary."".
  11. ^ "Cool, Strange, and Interesting Facts," fact 99. InnocentEnglish.com. Retrieved 2019-03-13.