What is the longest word in English?

Pile of words

English has hundreds of thousands of words, of which these are only a small sample. Powerbooktrance photo. CC-BY.

To figure out what is the longest word, we need to ask ourselves first what a “real” word is. In scientific usage, you can give chemicals names hundreds or even thousands of letters long by stringing together all sorts of word parts. Also, at least in theory, just as you could have an anti-missile, you could have an anti-anti-missile, an anti-anti-anti-missile and so on, and again come up with an arbitrarily long word.

So, it might be better to ask, what’s the longest word in a recognized dictionary? To that, the answer is fairly simple: pneumonoultramicroscopicsilicovolcanoconiosis, a 45-letter word for a lung disease that is listed in Webster’s New Millennium Dictionary of English, the Random House Dictionary and Merriam-Webster’s Medical Dictionary.

That word isn’t listed in all dictionaries, however. The longest word in the first edition of the Oxford English Dictionary, which might be considered the gold standard of standard English, was the 29-letter floccinaucinihilipilification, which involves estimating something as worthless.

Neither of those words, however, are used much in real life (and neither is listed in the American Heritage Dictionary). Do a web search for either one, and you’ll usually find it in an article about long words rather than being used for their meaning. Perhaps the longest word that has had real use (although it is used more today as an example of a long word) is antidisestablishmentarianism, which at 28 letters referred to the political belief opposing the elimination of the Church of England as the official church.

Incidentally, determining what is a real word also makes it difficult to give a clear designation of the longest words in other languages as well. But one designation for the longest word in Spanish is a word that has real-life use: electroencefalografistas, referring to medical professionals who operate a brain-monitoring machine.

Related questions:

  • What is the longest English word in common usage?What is the longest English word in common usage? The longest word in a recognized English language dictionary is pneumonoultramicroscopicsilicovolcanoconiosis, but few people would ever have used that word or heard it spoken. So what […]
  • Is it practise or practice, license or licence?Is it practise or practice, license or licence? What's the correct spelling of practice/practise and licence/license in every situation? As you probably already know, it depends on where you live, and how the words are being […]
  • How is the apostrophe used in English?How is the apostrophe used in English? Too often, the apostrophe is used badly. English teachers, newspaper editors and just about anyone with a eye for English grammar cringe almost daily when they when they see […]
  • What are parts of speech?What are parts of speech? "Parts of speech" refers to categories that are used by grammarians to describe how words are used in sentences. English has traditionally been viewed as having eight parts of speech, […]
  • Were “oranges” once called “noranges”?Were “oranges” once called “noranges”? A frequently-repeated etymology of the fruit that we call an "orange" goes like this: The fruit was not grown in England, and when the dock-hands unloaded the cargo ships they heard […]

  Need research? Quezi's researchers can answer your questions at uclue.com

Written by | 9,220 views | Tags: , , , ,


  • eiffel says:

    In our family we have a “house rule” that a word doesn’t count unless someone has used it with its genuine meaning in the past twelve months. This is a very useful rule for Scrabble, because it avoids the need to consult a dictionary (most of the time).
    By this line of reasoning, the longest word in the English language in our household would be supercalifragilisticexpialidocius at 33 letters. It’s surely every bit as real a word as floccinaucinihilipilification.

  • mvguy says:

    I like that Scrabble rule. If they made crossword puzzles following a rule like that, they’d be much easier.

    When I wrote this article, I tried to figure out what would be the longest word in everyday speech. I didn’t have much luck figuring out what would be an objective way to figure that out, but I’m open to suggestions.

  • eiffel says:

    That sounded interesting, so I’ve investigated and written up the longest word in everyday speech.

RSS feed for comments on this post.

Privacy Policy | Acknowledgements