What’s the Longest Word in English?

Spoiler alert: Despite what you might have heard, it’s not ‘antidisestablishmentarianism.’
It’s not one you’re likely to use in everyday conversation—but you will find it in an dictionary.
It’s not one you’re likely to use in everyday conversation—but you will find it in an dictionary. / Jamie Grill/The Image Bank/Getty Images

Forget antidisestablishmentarianism: If you can find a way to work pneumonoultramicroscopicsilicovolcanoconiosis into a conversation, congratulations! You’ve just managed to use the longest defined word you’ll find in any dictionary in everyday chatter. But also: We hope you’re feeling OK, as the 45-letter word is a disease that causes an inflammation of the lungs due to the inhalation of very fine silicate or quartz dust.

At least, that’s what it’s supposed to mean. The word was coined in the 1930s, probably by the president of the National Puzzlers’ League, “in imitation of polysyllabic medical terms,” according to the Oxford English Dictionary, “but occurring only as an instance of a very long word.” In other words, pneumonoultramicroscopicsilicovolcanoconiosis was a word created simply to be long.

That’s not as unusual as it might sound: Another pretty long word, floccinaucinihilipilification—meaning “the action or habit of estimating as worthless”—was created by mashing together four words in a Latin grammar book that all meant something with little value and adding -fication at the end. Compounding like that gives languages around the world many famously long words; it’s how Germans wound up with Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz, a 63-letter word that translates to “the law for the delegation of monitoring beef labeling” and was removed from law books in the country in 2013.

(Quick aside: While German is particularly famous for making long compound words, it’s a common feature of Germanic languages, including English. The key difference is that English often—but not always—uses spaces or hyphens when writing out especially long compounds. How much that space matters is perhaps debatable, but according to the Oxford Companion to the English Language, these compounds are, in theory, “indefinitely extensible.” They give Coventry car factory strike committee policy decision as an example, which is a paraphrase of “‘decision about policy made by a committee dealing with strikes in a factory that makes cars in Coventry.’” They note that, “In English, such expressions are not usually written as one word, as in German. Both languages, however, exploit very fully their capacity to form compounds and other multiple word groups.”)

There are even longer words than pneumonoultramicroscopicsilicovolcanoconiosis out there—you just won’t necessarily find them in a dictionary. According to Guinness, Nirantarāndhakāritā … lokān, “a compound ‘word’ of 195 Sanskrit characters (transliterating to 428 letters in the Roman alphabet),” is the longest word in the world; it translates to:

“In it, the distress, caused by thirst, to travelers was alleviated by clusters of rays of the bright eyes of the girls; the rays that were shaming the currents of light, sweet and cold water charged with the strong fragrance of cardamom, clove, saffron, camphor and musk and flowing out of the pitchers (held in) the lotus-like hands of maidens (seated in) the beautiful water-sheds, made of the thick roots of mixed with marjoram, (and built near) the foot, covered with heaps of couch-like soft sand, of the clusters of newly sprouting mango trees, which constantly darkened the intermediate space of the quarters, and which looked all the more charming on account of the trickling drops of the floral juice, which thus caused the delusion of a row of thick rainy clouds, densely filled with abundant nectar.”

And if you want to use the full name of a protein also called “titin,” you’ll need to set aside a serious chunk of time: Methionylthreonylthreonylglutaminylarginyl ... isoleucine stretches out to a whopping 189,819 letters and takes more than three hours to say. Other words, like the name of a single molecule of DNA, could eventually be rendered with well over a billion letters.

But according to Oxford Dictionaries, words like these are “regarded as chemical names rather than genuine words in the sense of meaningful items of vocabulary. The same is true of the formal names of chemical compounds. These can be almost unlimited in length … and many contain numerals, Roman and Greek letters, and other symbols, as well as ordinary letters. We don't tend to regard these terms as proper ‘words’”—and that’s why you won’t find them in any dictionary.

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