The longest word in English, and other word records

The longest word in the major English dictionaries is pneumonoultramicroscopicsilicovolcanoconiosis, at 45 letters. Merriam-Webster (n.d.-a) calls it "the longest word entered in most standard English dictionaries", and the Oxford English Dictionary enters it too. Longer strings exist: one protein's chemical name runs to 189,819 letters, which Merriam-Webster says "isn't technically a word". Our view: there is no single longest word, only records that hold under a stated rule, so this guide gives each record with the dictionary or record book that documents it.

EdCitation publishes this guide. On 3 October 2026 we read Merriam-Webster's long-words list and medical entry, six OED entries and its March 2011 release notes, Guinness World Records' pages, and the Folger text of Love's Labour's Lost. Both dictionaries' sites put a robot check in front of us, so their pages were read in archived copies, linked under References.

EdCitation never writes any part of anyone's work, and we say so with pride: every sentence you hand in, long words included, stays yours. EdCitation checks instead. Mechanics QA reads a finished paper by rule, down to the slips a spell-checker lets through, and the free Find sources and Verify references look after the sources behind it.

What is the longest word in English?

The longest word in a standard English dictionary is pneumonoultramicroscopicsilicovolcanoconiosis, 45 letters; the longest overall depends on what you allow as a word. Merriam-Webster notes that most English words over about 15 to 20 letters are scientific, meaningless or highly specialised.

Why the answer changes with the rule

Three rules decide it. First, must the word be in a dictionary? Merriam-Webster leaves out antidisestablishmentarianism, supercalifragilisticexpialidocious and floccinaucinihilipilification because they are mostly "used as examples of long words", while saying they are words that simply miss its criteria for entry. Second, does a chemical name count? Merriam-Webster treats the protein's as a description. Third, do place names count? They have their own section below. One oddity: Merriam-Webster says pseudopseudohypoparathyroidism is the only word in its dictionary with pseudo twice.

What does pneumonoultramicroscopicsilicovolcanoconiosis mean, and who made it up?

Pneumonoultramicroscopicsilicovolcanoconiosis names a lung disease caused by breathing in very fine silicate or quartz dust; Merriam-Webster's medical dictionary defines it as a pneumoconiosis of that kind (Merriam-Webster, n.d.-b). When it first appeared is better documented than who made it up.

What the dictionaries record

Merriam-Webster divides it into 19 syllables and gives a plural, pneumonoultramicroscopicsilicovolcanoconioses. The OED says it was formed within English by compounding, printed it in A Supplement to the OED (Volume III, 1982), revised it in 2006, and takes its earliest evidence from the New York Herald-Tribune in 1935 (Oxford University Press, n.d.-d). Dictionary.com (n.d.) is blunter, calling it a term "ostensibly referring to a lung disease caused by silica dust". The OED's own definition sits behind its subscription, and we did not read it.

The 1935 story, and what we could not confirm

The usual story names Everett Smith, president of the National Puzzlers' League, as its coiner in 1935, out to make the longest word. We found it only in a note from Vocabulary.com on Dictionary.com's entry. We did not read the 1935 newspaper, and the League's own history page does not mention the word, so treat the coiner's name as reported, not confirmed. The year is firmer: it matches the OED's earliest evidence.

Is antidisestablishmentarianism a real word?

Yes. The OED enters antidisestablishmentarianism, 28 letters, meaning opposition to the disestablishment of the Church of England, and notes that it usually appears where it is "given as an example of a very long word" (Oxford University Press, n.d.-a). Merriam-Webster leaves it out.

Born in a long-word contest, 1900

The OED's earliest evidence is a letter by A. Dalgleish in the Pall Mall Gazette of 30 November 1900, offering "the longest word controversy" what the writer called "a good, healthy word of twenty-eight letters". Its shorter parent, antidisestablishmentarian, is in the OED from 1892. The OED puts antidisestablishmentarianism in frequency band 2: between 0.001 and 0.01 uses per million words of modern written English.

Floccinaucinihilipilification and the Eton Latin Grammar

Floccinaucinihilipilification, 29 letters, means the action or habit of estimating something as worthless, and the OED labels it humorous (Oxford University Press, n.d.-b). It joins four Latin words meaning "at a small price" or "at nothing", floccī, naucī, nihilī and pilī, listed in what the OED calls "a well-known rule of the Eton Latin Grammar", and adds -fication. The earliest evidence is a 1741 letter by the writer William Shenstone, and the entry, first published in 1897, has not yet been revised. Even Walter Scott slipped on it: the OED quotes Scott's journal of 1829 spelling it floccipaucinihilipilification, marked sic.

Supercalifragilisticexpialidocious, older than the film

The OED dates supercalifragilisticexpialidocious, 34 letters, to 1931, more than thirty years before Walt Disney's Mary Poppins made it popular in 1964 (Oxford University Press, n.d.-e). Its first quotation, from the Syracuse University Daily Orange, spells it Supercaliflawjalisticexpialadoshus. A 1965 copyright suit against the film's makers failed, the OED records, the judge citing earlier spoken uses and differences between the songs. The OED defines it as a nonsense word, at first used mostly by children, expressing "excited approbation", and finds no evidence for the Latin and Greek roots people have proposed.

What is the longest word in Shakespeare?

The longest word in Shakespeare is honorificabilitudinitatibus, 27 letters, in Love's Labour's Lost. In Act 5, Scene 1, Costard teases the Boy: "thou art not so long by the head as honorificabilitudinitatibus" (Shakespeare, n.d.). Guinness lists it as the longest English word made strictly of alternating consonants and vowels, glossed "with honorableness" (Guinness World Records, n.d.-c). The OED enters an English form, honorificabilitudinity, borrowed from Latin honorificabilitudinitas, with its earliest evidence in 1656 from the antiquary Thomas Blount (Oxford University Press, n.d.-c). Which words Shakespeare used first is another question, answered in words Shakespeare is credited with.

Which English word has the most meanings?

The verb run has the most meanings in the OED: its March 2011 revision gave it 645 senses, counting phrases and idioms, and made it the largest single entry in the dictionary (Simpson, 2011). Before that, set held the record.

Set, put and run

Guinness still names set, with 430 senses in the 1989 Second Edition and an entry of 60,000 words, or 326,000 characters (Guinness World Records, n.d.-a). John Simpson, the OED's Chief Editor, wrote in 2011 that run was half as large again as the next-biggest entry, the verb put, and put unrevised set at 579 senses. He judged it "touch-and-go" whether set, once revised, would take back the first place it held in the first and second editions. Neither page explains why set has 430 senses in one and 579 in the other, so quote each figure with its source; whether set has since been revised, we could not confirm. For 1755, see Samuel Johnson's dictionary.

What other word records are there?

Guinness World Records keeps records for words with odd letter patterns, given here as each page states them. The pages carry no date and, apart from tattarrattat, name no dictionary, so treat them as Guinness's claims.

Notes on the table

Guinness calls strengthed archaic. Euouae is a medieval music term for the vowels of "seculorum Amen". Tattarrattat, Guinness says, is a nonce word meaning rat-a-tat; the OED's earliest evidence is James Joyce in 1922 (Oxford University Press, n.d.-f).

What is the longest place name?

The longest place name, by Guinness's count, is Bangkok's ceremonial name, 168 letters in its fullest transliteration, opening Krungthep Mahanakhon (Guinness World Records, n.d.-g). Merriam-Webster sets a narrower record: the longest place name in the English-speaking world is "thought to be" an 85-letter Māori name for a hill in New Zealand, Taumatawhakatangihangakoauauotamateaturipukakapikimaungahoronukupokaiwhenuakitanatahu, called Taumata for short.

The lake whose long name may be a newspaper's work

Merriam-Webster's longest place name in the United States is "possibly" Lake Chargoggagoggmanchauggauggagoggchaubunagungamaugg in Massachusetts, 49 letters, also called Webster Lake. The long name draws on the Nipmuc people's earlier names for the lake, but this version and its popular translation, Merriam-Webster says, appear to have been invented by a local newspaper editor. We tell that story, as the dictionary does, as unconfirmed.

A Welsh town in a crossword

Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch, a Welsh town's name of 58 letters by our count, holds Guinness's record for the longest word in a cryptic crossword: Roger Squires set it in the Telford Wrekin News in July 1979 (Guinness World Records, n.d.-h).

How do you cite a dictionary entry for a word record?

Cite the entry you read, with its dictionary, its date or "n.d.", and its address: a record is only as good as the page behind it.

1. Go to the dictionary's own entry, not a list of fun facts, and read its labels, such as humorous.
2. Note the entry's history. The OED shows when an entry was revised (antidisestablishmentarianism, March 2023) or that it has not been.
3. Keep the address. If the page sits behind a robot check, give an archived copy's address.
4. Build the reference in EdCitation's Cite a source, free, which takes a web address and lets you correct the page's details before the entry is built, in APA 7, MLA 9, Chicago 18 author-date, Harvard, IEEE or Vancouver. The OED's own form is covered in how the OED was made.
5. Check the finished list in Verify references. An entry with its own address is checked at the page; a page that shows no readable title, or a check for robots, comes back "could not check", never "not found".

How does EdCitation help when long words reach your paper?

EdCitation is, in our view, the best tool for the last read of a finished paper, because it checks by rule and never rewrites. Long words are where slips hide: the OED prints Walter Scott's 1829 spelling of floccinaucinihilipilification with a sic, and its first record of supercalifragilisticexpialidocious spells it another way entirely.

Mechanics QA, by rule

Mechanics QA gives a whole Word or PDF file the first read a marker gives it. It checks font, size, spacing, margins, title page, headings and the reference list against the APA 7 student paper; finds comments, tracked changes, placeholders and template text left in the file; matches each citation to the list and looks each reference up in the publisher's record; and flags figures that do not add up or disagree between sections, and the slips a spell-checker lets through. No model reads the paper. Each finding names the rule it broke and its fix, marked where it sits. A free account runs three checks a month; Pro, at $8 a month, has no limit (pricing).

Find sources, for the research behind a word

Find sources, free with no account, searches about 300 million published works. On 3 October 2026 we searched "longest words in English": it returned 104,400 results from OpenAlex, led by a 2012 paper, Kuperman, Stadthagen-González and Brysbaert's "Age-of-acquisition ratings for 30,000 English words", and none of the first ten was about word records. Records like these live in dictionaries, not journals, which is why this guide rests on the OED and Merriam-Webster.

Quick questions

What is the longest word in the English dictionary?

Pneumonoultramicroscopicsilicovolcanoconiosis, 45 letters, a lung disease from very fine dust. Merriam-Webster calls it the longest word in most standard dictionaries; the OED's earliest evidence is from 1935.

Is supercalifragilisticexpialidocious in the dictionary?

It is in the OED, with evidence from 1931, but not in Merriam-Webster, which leaves out words used mainly as examples of long words.

Which English word has the most meanings?

In the OED, the verb run: 645 senses, counting phrases, after its 2011 revision. Guinness still lists set, with 430 senses in the 1989 Second Edition.

What is the longest one-syllable word?

Guinness lists scraunched and the archaic strengthed, 10 letters each. Strengths, at nine letters, is its longest word with only one vowel.

Can EdCitation check my essay for slips a spell-checker misses?

Yes, within a rule-by-rule read: EdCitation's Mechanics QA, in Pro, checks formatting, citations, numbers and language, including the slips a spell-checker lets through, and marks each finding with its fix. It never rewrites your sentences.

References

• Dictionary.com. (n.d.). Pneumonoultramicroscopicsilicovolcanoconiosis. In Dictionary.com. Retrieved 3 October 2026, from https://www.dictionary.com/browse/pneumonoultramicroscopicsilicovolcanoconiosis
• Guinness World Records. (n.d.-a). English word with the most meanings. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/english-word-with-the-most-meanings
• Guinness World Records. (n.d.-b). Longest English word consisting only of vowels. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/longest-english-word-consisting-only-of-vowels
• Guinness World Records. (n.d.-c). Longest English word consisting strictly of alterating [sic] consonants and vowels. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/longest-english-word-consisting-strictly-of-alterating-consonants-and-vowels
• Guinness World Records. (n.d.-d). Longest English word with letters arranged in alphabetical order. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/longest-english-word-with-letters-arranged-in-alphabetical-order
• Guinness World Records. (n.d.-e). Longest monosyllabic English words. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/longest-monosyllabic-english-words
• Guinness World Records. (n.d.-f). Longest palindromes. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/78623-longest-palindromes
• Guinness World Records. (n.d.-g). Longest place name. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/67273-longest-place-name
• Guinness World Records. (n.d.-h). Longest word in a crossword. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/75821-longest-word-in-a-crossword
• Guinness World Records. (n.d.-i). Longest word in the English language with only one vowel. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/longest-word-in-the-english-language-with-only-one-vowel
• Guinness World Records. (n.d.-j). Longest word in the English language without any of the five main vowels. Retrieved 3 October 2026, from https://www.guinnessworldrecords.com/world-records/78621-longest-word-in-the-english-language-without-any-of-the-five-main-vowels
• Merriam-Webster. (n.d.-a). The longest long words list. Wordplay. https://web.archive.org/web/20260928231109/https://www.merriam-webster.com/wordplay/longest-words-ever
• Merriam-Webster. (n.d.-b). Pneumonoultramicroscopicsilicovolcanoconiosis. In Merriam-Webster.com medical dictionary. https://web.archive.org/web/20260731213730/https://www.merriam-webster.com/medical/pneumonoultramicroscopicsilicovolcanoconiosis
• Oxford University Press. (n.d.-a). Antidisestablishmentarianism, n. In Oxford English Dictionary. https://web.archive.org/web/20240111093722/https://www.oed.com/dictionary/antidisestablishmentarianism_n
• Oxford University Press. (n.d.-b). Floccinaucinihilipilification, n. In Oxford English Dictionary. https://web.archive.org/web/20240713135816/https://www.oed.com/dictionary/floccinaucinihilipilification_n
• Oxford University Press. (n.d.-c). Honorificabilitudinity, n. In Oxford English Dictionary. https://web.archive.org/web/20250503225350/https://www.oed.com/dictionary/honorificabilitudinity_n?tab=meaning_and_use
• Oxford University Press. (n.d.-d). Pneumonoultramicroscopicsilicovolcanoconiosis, n. In Oxford English Dictionary. https://web.archive.org/web/20240702073422/https://www.oed.com/dictionary/pneumonoultramicroscopicsilicovolcanoconiosis_n?tab=meaning_and_use
• Oxford University Press. (n.d.-e). Supercalifragilisticexpialidocious, adj. In Oxford English Dictionary. https://web.archive.org/web/20260414021124/https://www.oed.com/dictionary/supercalifragilisticexpialidocious_adj?tl=true
• Oxford University Press. (n.d.-f). Tattarrattat, n. In Oxford English Dictionary. https://web.archive.org/web/20240423081517/https://www.oed.com/dictionary/tattarrattat_n
• Shakespeare, W. (n.d.). Love's labor's lost (Act 5, Scene 1). Folger Shakespeare Library. Retrieved 3 October 2026, from https://www.folger.edu/explore/shakespeares-works/loves-labors-lost/read/5/1/
• Simpson, J. (2011). March 2011 update. Oxford English Dictionary. https://web.archive.org/web/20170729173342/http://public.oed.com/the-oed-today/recent-updates-to-the-oed/previous-updates/march-2011-update/