The 13 Longest Words in the English Language

How many of them can you pronounce—or spell?!

Some folks receive compliments on their general vocabulary, while others are celebrated for their knowledge of totally obscure, highly specialized terms. If you're reading this article, then you're about to become one of the latter, because we've put together a list of some of the longest words the English language has to offer. Most of the terms below are examples of affixation, the process of adding a letter or group of letters to the end of a word, thereby changing the meaning. Others are specific to the medical space and some—OK, one—was invented for the silver screen but now resides in dictionaries worldwide. Read on to see how many of the longest words you've heard of—bonus points if you make an attempt at pronouncing them.

RELATED: 60 Words People Pronounce Differently Across the U.S.

The Longest English Words, Ranked

1. Methionylthreonylthreonylglutaminyl(189,819 letters)

Molecular structure of chemical compounds and organic chemistry concept with educational plastic model of ethanol molecule isolated on blue background
Victor Moussa/Shutterstock

When we say this one is a mouthful, we mean it. The word is so long, we actually had to insert an ellipsis not even halfway through.

It would take more than 50 pages and 189,819 characters to actually spell this particular word in full. Those who are really dedicated to expanding their lexicon are invited to watch tutorials on how to pronounce the longest word in English, but be sure you have the time before you commit. The term—which is a chemical name for a protein— takes more than three hours to say.

2. Pneumonoultramicroscopicsilicovolcanoconiosis (45 letters)

A young man is standing outside on the street and coughing.

This 45-letter term refers to a lung disease caused by the inhalation of sand and ash. Surprisingly, this word hasn't been in use for very long. It was coined by a man named Everett M. Smith, the then-president of the National Puzzlers' League, in 1935. Smith came up with the phrase as a sarcastic take on long medical terms and as a synonym for silicosis—a lung disease caused by inhaling very fine silicate or quartz dust.

3. Hippopotomonstrosesquippedaliophobia (36 letters)

image of a woman over a black background looking scared
Benoit Daoust/Shutterstock

You may have noticed the "phobia" tacked on to the end here, which implies a fear of something. Well, in its entirety, the term is actually defined as a fear of long words. How's that for a full circle moment?

RELATED: 40 Words That Will Instantly Reveal Your True Age.

4. Supercalifragilisticexpialidocious (34 letters)

Julie Andrews and Dick Van Dyke in Mary Poppins
Buena Vista Distribution

We promised you there would be a little movie magic incorporated into our list, and here it is. Cinephiles will recognize this phrase as a standout moment in the Disney classic, Mary Poppins. In her world, the word means extraordinarily good or wonderful.

5. Pseudopseudohypoparathyroidism (30 letters)

Lab worker preparing test blood for detection of antibodies and infections

And here we bring you yet another medical term. This long word refers to a relatively mild form of pseudohypoparathyroidism, a rare inherited disorder characterized by abnormal levels of calcium and phosphorus in the blood.

6. Floccinaucinihilipilification (29 letters)

Close up on hand throwing wads of paper into full wastebasket
Brian A Jackson/Shutterstock

This word is a bit of a mystery because some sources—including Merriam-Webster—maintain it's not even a word, refusing to list it in their directories. Others, however, accept its definition as the act or habit of describing something as valueless or unimportant.

7. Antidisestablishmentarianism (28 letters)

The British flag painted on white paper with watercolor
Aleksey Klints/Shutterstock

These twenty-eight letters make up the only word on our list with strong ties to politics. The term references the political movement that fought to disestablish the Church of England as the official state church of England, Ireland, and Wales.

RELATED: The 20 Hardest Languages to Learn From Around the World.

8. Honorificabilitudinitatibus (27 letters)

Shakespeare bust stone sculpture portrait
adolf martinez soler/Shutterstock

Not only is "honorificabilitudinitatibus" the longest word to appear in Shakespeare's works, but it's also the longest word in English featuring alternating consonants and vowels. It means the state of being able to achieve honors.

9. Thyroparathyroidectomized (25 letters)

Endocrinologist examining throat of young woman in clinic

Thyroparathyroidectomized is another medical term, this one referring to the excision of both the thyroid and parathyroid glands.

10. Dichlorodifluoromethane (23 letters)

Hand using a spray on white background
Yeti studio/Shutterstock

If you aren't a practicing chemist, then you're not likely to ever need to use this word. Still, you never know what might come up at a trivia night. Dichlorodifluoromethane is a colorless gas usually sold under the brand name Freon-12. The substance is typically used as a refrigerant or an aerosol spray propellant.

RELATED: 70 English Idioms That'll Help You Become Fluent in No Time

11. Incomprehensibilities (21 letters)

Man sitting on couch, holding phone and shrugging
Kateryna Onyshchuk/Shutterstock

Now that we're finally down to 21 letters, we'll probably hit on some you can already define and maybe even use on a regular basis. An affixation of "incomprehensible," incomprehensibilities refers to the state of something being impossible to understand or comprehend. Back in the '90s, the term actually set the record as the longest word in "common usage."

12. Xenotransplantation (19 letters)

Hands pulling on blue protective gloves
Nadezhda Mikhalitskaia/Shutterstock

Once again, we're back in the medical space. This word can be used in regards to any procedure that involves the transplantation, implantation, or infusion from one species to another.

13. Sesquipedalianism (17 letters)

fountain pen on paper with ink text on the paper closeup

Here's another word that's somewhat self-referential. Sesquipedalianism is 17 letters long and its definition is the tendency to use long words. Its origins can be traced back to the Roman poet Horace, who in a treatise on the art of poetry wrote that—at least in some circumstances—poets must avoid "sesquipedalia verba," a sequence of Latin words meaning "words (verba) a foot and a half long (sesquipedalia)." Talk about an early and ancient sense of humor!

RELATED: Tongue Twisters So Good, Your Mouth May Never Be the Same

The Longest One-Syllable Word in English

While the multisyllabic picks listed above are indeed difficult to read and even more challenging to pronounce, there is something to admire about short-sounding words that stretch far across the page.

At 10 letters, squirreled takes the record for the longest one-syllable word in English. It's followed close behind by strengths, the longest English word containing just one vowel. Other words that fall into the same category include:

  • Scratched
  • Scrunched
  • Stretched
  • Schlepped

The Longest Word(s) In English That Don't Contain a Vowel

Tsk-tsk (as in what you might say to scold someone) may look and sound funny, but it's actually listed in the dictionary. This word sets the record for the longest word that does not contain a vowel. If we go by the logic that the letter "Y" is in fact a consonant (though it often behaves as a vowel), then we can also group the following words in the same category:

  • Symphysy
  • Twyndyllyngs
  • Rhythms

Other Honorable Mentions

Before we let you go: Euouae is a six-letter musical term that holds a Guinness World Record for the longest English word consisting of only vowels. And finally, there's the fantastically long Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch, which is actually a place you can visit. It's the name of a large village on the island of Anglesey, Wales. At 58 letters, the township holds the record of the longest regional name in an English-speaking country.

Wrapping Up

That's it for our list of the longest English words, but be sure to check back in with us soon for even more awesome trivia. You can also sign up for our newsletter to enjoy similar content, as well as the latest in wellness, entertainment, and travel.

Carrie Weisman
Carrie Weisman oversees all SEO efforts at Best Life. She specializes in content optimization and editorial marketing. Read more
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