The Longest English Words


Let’s start off with a word related to the business of “longest words.” Sesquipedalianism is the tendency to use long words. And, a sesquipedal is a person who has sesquipedalian tendencies.

The word is traced to the ancient Roman poet Horace, who in a treatise on crafting poetry, wrote that in certain circumstances, one must avoid sesquipedalia verba, a Latin construct meaning “words a foot and a half long.” Horace clearly had a sense of humor. The word is still in use today, and in fact, was a "Word of the Day" not long ago.

WATCH: We Asked These People What Words They Always Say Wrong ...


There are a number of very long words in the medical and science fields, and we don't want to add words strictly from that arena. But, the longest one in that field is pneumonoultramicroscopicsilicovolcanoconiosis (that’s forty-five characters), which is the manufactured name of an occupational lung disease (more commonly known as silicosis) resulting from inhaling crystalline silica dust).

Some discount this one from the record books, stating it is an "artificial" word that was reportedly coined (or created) for the purpose of being the longest word in an official dictionary, back in 1935. But, it's still in the dictionary today so we're including it!


We include pseudopseudohypoparathyroidism, another medical/science-derived term, because this one is the longest non-coined word (not fabricated but natural) to appear in major dictionaries. We define pseudo as “not actually but having the appearance of; pretended; false or spurious; sham.”

You might notice the appearance of pseudo twice: That’s because this simulates the symptoms of pseudohypoparathyroidism, a disorder that acts as if the body is short on the parathyroid hormone when it’s actually producing enough (hypo means below or under). So, there are two levels of faking it going on here.


Antidisestablishmentarianism is a prime example of a sesquipedalian word, as it’s actually the longest “natural” or non-coined word in the English language that isn’t scientific in origin. The word isn’t really used today, except in reference to very long words (like here).

The word pertains to the 19th-century opposition of (anti) the dismantling of the Anglican Church’s place as the state church of England, Ireland, and Wales (disestablishment).


Here’s one that is also a bit of a Mobius strip: floccinaucinihilipilification is a rarely-used word that means "something of little or no value," and it is usually used in reference to itself!

From the 1700s, the word contains four Latin words that all mean “of little value” or “for nothing”: flocci, nauci, nihili, pili.


The longest word in “common usage” is incomprehensibilities; 21 characters that look pretty friendly on the page. But, when was the last time you actually said it?

We define incomprehensible as “impossible to comprehend or understand,” and this expanded version of the word seems pretty practical. We think you'll be using this long word pretty often now that you've read this . . . .


If you look closely at the spelling, you’ll notice a peculiar thing about this word with 16 letters. It does not repeat any letter, each character is used only once. This word is known as an isogram in the field of logology (or “recreational linguistics”). The longest isogram is actually subdermatoglyphic, at 17 characters.

But, since subdermatoglyphics, related to the study of fingerprints, lines, and hand shapes, is a bit scientific and certainly not one that is used often, we’re spotlighting uncopyrightables instead, because it's one we can all remember. It means, of course, "items that are unable to be copyrighted," such as catch phrases or recipes.


We appreciate the uniqueness of this word. Most English dictionaries accept this spelling (some prefer one l), which makes squirrelled ("to hide something of value away in a safe place") the longest word pronounced in one syllable. It’s like squirrelling away your syllables for a rainy day.


There are a few words in the 22-letter range that are not scientific, and not coined, but they are used pretty rarely (counterrevolutionaries, deinstitutionalization). But, the most common one (OK, it's 20-characters . . .) is uncharacteristically, which means "to do something that is not typical of a particular person or thing."


This is that company that messed up the 2017 Oscars . . . . PriceWaterhouseCoopers really does spell their name like that, clocking in at 22 characters. Not sure why they didn’t just go for some nice spacing and 24 characters, but they can put that thought in their unwanted-layout-related-advice file.


This is the longest word (well not really word, but item) banned by the government: dichlorodiphenyltrichloroethane, or as it’s known by the easier to pronounce abbreviation, DDT. Agricultural use of the chemical was banned back in 1973.


This is the longest United States lake name we could find. So, let’s take a dip into Lake Char­gogg­a­gogg­man­chaugg­a­gogg­chau­bun­a­gung­a­maugg. Seriously. That’s 45 characters! It also goes by Lake Chaubunagungamaug and Lake Webster, and is located in Webster, Massachusetts.


This is the longest word using vowels in order (exactly once). A tip of the blue cap to Mental Floss for this one. The 11-letter AEIOU word is abstentious, which means you don’t indulge to excess (a variant of the word abstain).


We thought we’d end with a word that might evoke a happy childhood memory. If you've seen the 1964 movie Mary Poppins, you might remember singing along to the song, “Supercalifragilisticexpialidocious,” which had the rare effect of making a kid feel both brainy and clever.

The made-up word was Mary’s way of expressing delight; however, the word is in major dictionaries today. We define it as “a nonsense word by children to express approval or to represent the longest word in English.” Delightful!

Phew, this slideshow was a mouthful . . . .

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