What's the Longest Word in the World? Here are 12 of Them, By Category

Rebecca O'Connell
Rebecca O'Connell

Antidisestablishmentarianism, everyone’s favorite agglutinative, entered the pop culture lexicon on August 17, 1955, when Gloria Lockerman, a 12-year-old girl from Baltimore, correctly spelled it on The $64,000 Question as millions of people watched from their living rooms. At 28 letters, the word—which is defined as a 19th-century British political movement that opposes proposals for the disestablishment of the Church of England—is still regarded as the longest non-medical, non-coined, nontechnical word in the English language, yet it keeps some robust company. Here are some examples of the longest words by category.

1. METHIONYLTHREONYLTHREONYGLUTAMINYLARGINYL … ISOLEUCINE 

Note the ellipses. All told, the full chemical name for the human protein titin is 189,819 letters, and takes about three-and-a-half hours to pronounce. The problem with including chemical names is that there’s essentially no limit to how long they can be. For example, naming a single strand of DNA, with its millions and millions of repeating base pairs, could eventually tab out at well over 1 billion letters.

2. LOPADOTEMACHOSELACHOGALEOKRANIOLEIPSAN …P TERYGON

The longest word ever to appear in literature comes from Aristophanes’ play, Assemblywomen, published in 391 BC. The Greek word tallies 171 letters, but translates to 183 in English. This mouthful refers to a fictional fricassee comprised of rotted dogfish head, wrasse, wood pigeon, and the roasted head of a dabchick, among other culinary morsels. 

3. PNEUMONOULTRAMICROSCOPICSILICOVOLCANOCONIOSIS

At 45 letters, this is the longest word you’ll find in a major dictionary. An inflated version of silicosis, this is the full scientific name for a disease that causes inflammation in the lungs owing to the inhalation of very fine silica dust. Despite its inclusion in the dictionary, it’s generally considered superfluous, having been coined simply to claim the title of the longest English word.

4. PARASTRATIOSPHECOMYIA STRATIOSPHECOMYIOIDES 

The longest accepted binomial construction, at 42 letters, is a species of soldier fly native to Thailand. With a lifespan of five to eight days, it’s unlikely one has ever survived long enough to hear it pronounced correctly.

5. PSEUDOPSEUDOHYPOPARATHYROIDISM

This 30-letter thyroid disorder is the longest non-coined word to appear in a major dictionary.

6. FLOCCINAUCINIHILIPILIFICATION

By virtue of having one more letter than antidisestablishmentarianism, this is the longest non-technical English word. A mash-up of five Latin roots, it refers to the act of describing something as having little or no value. While it made the cut in the Oxford English Dictionary, Merriam-Webster volumes refuse to recognize it, chalking up its existence to little more than linguistic ephemera.

7. SUBDERMATOGLYPHIC

At 17 characters, this is the longest accepted isogram, a word in which every letter is used only once, and refers to the underlying dermal matrix that determines the pattern formed by the whorls, arches, and ridges of our fingerprints. 

8. SQUIRRELLED

Though the more commonly accepted American English version carries only one L, both Oxford and Merriam-Webster dictionaries recognize this alternate spelling and condone its one syllable pronunciation (think “world”), making it the longest non-coined monosyllabic English word at 11 letters.

9. ABSTENTIOUS

One who doesn’t indulge in excesses, especially food and drink; at 11 letters this is the longest word to use all five vowels in order exactly once.

10. ROTAVATOR 

A type of soil tiller, the longest non-coined palindromic word included in an English dictionary tallies nine letters. Detartrated, 11 letters, appears in some chemical glossaries, but is generally considered too arcane to qualify.

11. and 12. CWTCH, EUOUAE

The longest words to appear in a major dictionary comprised entirely of either vowels or consonants. A Cwtch, or crwth, is from the Welsh word for a hiding place. Euouae, a medieval musical term, is technically a mnemonic, but has been accepted as a word in itself. 

Quid Pro Quo Has a Nefarious Etymology

MangoStar_Studio/iStock via Getty Images
MangoStar_Studio/iStock via Getty Images

While some altruists will happily lend a hand without expecting anything in return, most of the world runs on the idea that you should be compensated in some way for your goods and services.

That’s quid pro quo, a Latin phrase which literally means “something for something.” In many cases, one of those “somethings” refers to money—you pay for concert tickets, your company pays you to teach your boss how to open a PDF, etc. However, quid pro quo also applies to plenty of situations in which no money is involved. Maybe your roommate agreed to lend you her favorite sweater if you promised to wash her dishes for a month. Or perhaps, in return for walking your neighbor’s dog while he was on vacation, he gave you his HBO login credentials.

No matter the circumstances, any deal in which you give something and you get something falls under the category of quid pro quo. According to The Law Dictionary, “it is nothing more than the mutual consideration which passes between the parties to a contract, and which renders it valid and binding.” In other words, if everyone on both sides understands the expectation that something will be given in return for a good or service, your contract is valid.

Based on that definition, quid pro quo hinges on transparency; all parties must understand that there’s an exchange being made. However, this wasn’t always the case. As the Columbia Journalism Review reports, Merriam-Webster’s dictionary entry states that quid pro quo was used in 16th-century apothecaries to denote when one medicine had been substituted for another, “whether intentionally (and sometimes fraudulently) or accidentally.”

So, if you were an unlucky peasant with a sore throat, it’s possible your herbal remedy could’ve been swapped out with something less effective—or even dangerous. Though Merriam-Webster doesn’t offer any specific examples of how or why this happened, it definitely seems like it would have been all too easy to “accidentally” poison your enemies during that time.

Just a few decades later, the term had gained enough popularity that people were using it for less injurious instances, much like we do today.

[h/t Columbia Journalism Review]

40 Words That Start With X

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arthobbit/iStock via Getty Images

When the lexicographer Dr. Samuel Johnson put together his Dictionary of the English Language in 1755, there weren't a lot of words that started with X; he even included a disclaimer at the bottom of page 2308 that read, “X is a letter which though found in Saxon words, begins no word in the English language.” Noah Webster went one better when he published his Compendious Dictionary in 1806 that included a single X-word, xebec, defined as “a small three-masted vessel in the Mediterranean Sea.” Although, by the time he compiled his landmark American Dictionary in 1828, that total had risen to 13.

X has never been a common initial letter in English, and even with today’s enormous vocabulary you can still only expect around 0.02 percent of the words in a dictionary to be listed under it. But why not try boosting your vocabulary with these 40 words that start with X.

1. X

On its own, the letter X is listed in the Oxford English Dictionary as a verb meaning “to cross out a single letter of type.” X. X. in Victorian slang meant “double-excellent,” while X. X. X. described anything that was “treble excellent.”

2. XANTHIPPE

Xanthippe was the name of Socrates’ wife, who, thanks to a number of Ancient Greek caricatures, had a reputation for henpecking, overbearing behavior. Consequently her name can be used as a byword for any ill-tempered or cantankerous woman or wife—as used in Shakespeare’s Taming of the Shrew.

3. XANTHOCOMIC

Explosion of yellow powder against a white background
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Xanthos was the Ancient Greek word for yellow, and as such is the root of a number of mainly scientific words referring to yellow-colored things. So, if you’re xanthocomic, you have yellow hair; if you’re xanthocroic you have fair hair and pale skin; and if you’re xanthodontous, you have yellow teeth.

4. X-CATCHER

In old naval slang, an X-catcher or X-chaser was someone who was good at math—literally someone good at working out the value of x.

5. X-DIVISION

Victorian slang for criminals or pickpockets, or people who make a living by some underhand means.

6. X-DOUBLE-MINUS

Young boy with a terrified expression on his face
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1960s slang for something really, really terrible.

7. XENAGOGUE

Derived from the same root as xenophobia, a xenagogue is someone whose job it is to conduct strangers or to act as a guide while…

8. XENAGOGY

… a xenagogy is a guidebook.

9. XENIAL

A young man fist bumps his musician friend
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The adjective xenial is used to describe a friendly relationship between two parties, in particular between a hospitable host and his or her guests, or diplomatically between two countries.

10. XENIATROPHOBIA

Don’t like going to see doctors you don’t know? Then you’re xeniatrophobic.

11. XENIUM

A xenium is a gift or offering given to a stranger, which in its native Ancient Greece would once have been a lavish feast or a refreshing spread of food and fruit. In the 19th century art world, however, xenium came to refer to a still-life painting depicting something like a extravagant display of food or a bowl of fruit.

12. XENIZATION

A young woman traveling with her camera and backpack
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A 19th century word meaning “the act of traveling as a stranger.”

13. XENOCRACY

A government formed by foreigners or outsiders is a xenocracy. A member of one is a xenocrat.

14. XENODOCHEIONOLOGY

Defined as “the lore of hotels and inns” by Merriam-Webster.

15. XENODOCHIUM

A young woman uses her cellphone at a hostel in India
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A guesthouse or hostel, or any similar stopping place for travelers or pilgrims.

16. XENODOCHY

A 17th century word for hospitality. If you’re xenodochial then you like to entertain strangers.

17. XENOGLOSSY

The ability to speak a language that you’ve apparently never learnt.

18. XENOLOGY

An illustration of an alien waving at the camera
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The scientific study of extraterrestrial phenomena is xenology. The study of extraterrestrial life forms is xenobiology.

19. XENOMANIA

The opposite of xenophobia is xenomania or xenophilia, namely an intense enthusiasm or fondness for anything or anyone foreign.

20. XENOMORPH

Something unusually or irregularly shaped is a xenomorph—which is why it’s become another name for the eponymous creature in the Alien film franchise.

21. XENOTRANSPLANTATION

Surgeons operating on a patient
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Transplanting organic matter from a non-human into a human (like a pig’s heart valve into a human heart) is called xenotransplantation. Whatever it is that’s transplanted is called the xenograft.

22. XERIC

An ecological term used to describe anywhere extremely dry or arid. If it’s xerothermic, then it’s both dry and hot.

23. XERISCAPE

If you live in a xeric area, then you’ll have to xeriscape your garden. It’s the deliberate use of plants that need relatively little moisture or irrigation to landscape an arid location.

24. XEROCHILIA

Woman applies lip balm while outside during the winter
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The medical name for having dry lips. Having a dry mouth is xerostomia.

25. XEROCOPY

A xerographic copy of a document—or, to put it another way, a photocopy.

26. XEROPHAGY

The eating of dry food is xerophagy. It mightn’t sound like it, but it was originally a religious term.

27. XESTURGY

The proper name for the process of polishing.

28. XILINOUS

A pile of soft cotton against a white background
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Something described as xilinous resembles or feels like cotton …

29. XIPHOID

… while something described as xiphoid resembles a sword.

30. XOANON

Derived from the Greek for “carve” or “scrape,” a xoanon is a carved idol of a deity.

31. XTAL

Large double quartz crystal against a white background
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An abbreviation of “crystal,” according to the OED.

32. XYLOGRAPHER

A 19th century word for a wood engraver.

33. XYLOID

Why say that something is “woody” when you can say that it’s xyloid?

34. XYLOPOLIST

Pile of wood logs ready for sale
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A 17th century formal name for a timber merchant.

35. XYLOTOMOUS

Describes anything or anyone particularly good at wood-cutting or wood-boring.

36. XYRESIC

Means “razor-sharp.”

37. XYROPHOBIA

A pile of razor blades
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The fear of being close to or touching sharp implements.

38. XYLANTHRAX

Nowhere near as nasty as it sounds, this is just an old name for what we now call charcoal.

39. XYSTUS

A type of covered walkway or portico.

40. X.Y.Z.

Late 19th century slang for a journalist who takes on any work going, or else 18th century slang for a dandyish or “exquisite” young man.

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