The Longest Words in English (and Some Record-Breaking Oddities)
Ask what the longest word in English is and you will get several different answers, because it depends on what you count. Technical terms, made-up words and everyday vocabulary all have their own champions. Here are the most famous long words, followed by some curious records we checked against our own dictionary.
The famous long words
| Word | Letters | What it means |
|---|---|---|
| pneumonoultramicroscopicsilicovolcanoconiosis | 45 | A lung disease caused by inhaling very fine silica dust. It was coined in the 1930s, deliberately, to be a very long word, and has since appeared in major dictionaries. |
| supercalifragilisticexpialidocious | 34 | A nonsense word meaning wonderful, made famous by the 1964 film Mary Poppins. |
| floccinaucinihilipilification | 29 | The act of judging something to be worthless. A Latin-based word that is mostly used for its length. |
| antidisestablishmentarianism | 28 | Opposition to removing the Church of England's status as the official state church, a political debate of the 19th century. |
Scientific names for chemicals can be far longer still, running to thousands of letters, but most people do not count them as words in the ordinary sense.
The longest everyday words
Our dictionary of about 168,000 words includes words up to 15 letters, the size of a Scrabble board. Among the longest that you will see in everyday writing are:
congratulations, straightforward, troubleshooting, internationally, accomplishments, acknowledgement, confidentiality, characteristics, all 15 letters.
Records worth knowing
We checked each of these against our own word list:
- No letter used twice: UNCOPYRIGHTABLE and DERMATOGLYPHICS (the study of skin patterns such as fingerprints) are 15 letters long without repeating a single letter.
- Only one vowel: among everyday words, STRENGTHS has nine letters and just one vowel. The rarer POLYRHYTHMS manages eleven.
- No vowels at all: RHYTHMS has seven letters and no A, E, I, O or U, relying on Y instead.
- All five vowels in order: FACETIOUS and ABSTEMIOUS contain A, E, I, O and U exactly once each, in alphabetical order. Add -LY and they still do.
- Five vowels in a row: QUEUEING contains U, E, U, E and I one after another.
- Typed on one row: TYPEWRITER, REPERTOIRE, PROPRIETOR and PERPETUITY can all be typed using only the top row of letters on a standard keyboard, ten letters each.
Play with long words
Long words are great for a simple game: pick one, such as CONGRATULATIONS, and see how many shorter words you can make from its letters. Our word unscrambler will show you every one you missed. If you prefer a puzzle that reads the same both ways, see our guide to palindromes.
Related reading: Palindromes · British vs American spelling
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