What’s the longest word you know? A lengthy German word, or a Welsh name? One of those pesky long word combinations for numbers in French? Lots of people think “antidisestablishmentarianism” is the longest English word. Learning pronunciation can be hard, and when you trip up, it can leave you thinking, “This feels like the longest word in the world!” But just you wait until you see what we’ve got in store. We went on a hunt for the longest word in the world, and I’m excited to share what we found! Be warned, if you suffer from hippopotomonstrosesquippedaliophobia, the fear of long words, you may want to look away now!

what is the longest word in the world overlapping books mosalingua

The Longest Word in the World and Other Weird Wordy Wonders

We’re going to get into figuring out the longest word in history in a miunte. But first, maybe you’d like to know how to pronounce hippopotomonstrosesquippedaliophobia. Click play to listen:

When Is the Longest Word Actually a Word?

Before we start looking for the longest word, we have to put in a word… about words! There are some disputes about what counts as the longest word. Yes, you read that right. People actually argue about this stuff! Merriam-Webster has a very strict set of rules for what gets into their dictionary. And they all depend on usage. For a word to make the cut, it has to meet three criteria:

  1. It has to be commonly used
  2. It has to have sustained usage (this means that it has to be used across long periods of time)
  3. It must be meaningful

So if you’re thinking of breaking the world record by making up a random word, sorry! It won’t count. But why do these rules even matter? Surely a word is a word? Or not! Let’s take a look.

The World’s Longest Technical Words

Henry VIII is the longest English word antidisestablishmentarianism

If you ask an English speaker, they will probably say that the longest word they know is “antidisestablishmentarianism.” You have to hand it to them, that’s a mouthful! It means opposition to the disestablishment of the Church of England, and it was used (a little bit) when Henry VIII split from the Catholic Church in the 19th century. But Merriam-Webster hates this word. They hate it so much, they’ve made a statement about why it’s not in any of their dictionaries. There’s no real record of it ever being used meaningfully, so they refuse to count it as a word. So, unfortunately, what most people say is the longest word in the English language isn’t a word at all.

So, what is the longest word in the Merriam-Webster dictionary? According to MW, “electroencephalographically” is the longest English word. Try saying it; it might just sound like you’ve sneezed! It’s a type of examination doctors use on their patients’ brains. Probably not a word you’d say everyday… unless you work in a hospital, that is.

Some say the longest word in the English language is the chemical name of titin, the largest known protein, which is a whopping 189,819 letters long. Apparently, it would take you over 3.5 hours to pronounce it in full. That’s 42 days’ worth of flashcard revision on the MosaLingua app! If you wanted to post this word on Twitter, you’d have to put it in over 1355 separate tweets! But again, not exactly a word you’re likely to hear when chatting with friends.

What’s Really the Longest Word You’ll Hear in English?

Enough of the medical mumbo-jumbo! Unless you work for a lab or a dictionary, you’re not going to hear pneumonoultramicroscopicsilicovolcanoconiosis or pseudopseudohypoparathyroidism any time soon. Our quest for the longest word you’re likely to hear in English continues.

What about the famous tongue-twister from Mary Poppins, supercalifragilisticexpialidocious? Whether you see it, spell it, or say it, this word has a whopping 34 letters. Could be a strong contender as the longest word in English, right? We’d love for this magical, musical word to be our winner, but it’s not really that meaningful, and you probably won’t hear it much either! So if you are sticking to the rules, this one doesn’t cut it in the competition for the longest word

In the 1990s, “incomprehensibilities” took the number one spot for the longest word in the English language. With twenty-one letters, this is probably one of the longest English words in common usage.

What About the Longest Word in the World?

English might be popular, but it’s not the only language in the world, and it definitely doesn’t have the longest words in the world! In English, we tend to keep things short and sweet, and we love contractions like can’t, don’t and won’t. But there are plenty of languages (we’re looking at you, German!) that love sticking words together to create huge long words, called compounds. These are called agglutinative languages. They include German (of course), Japanese, Turkish, Korean, and Hungarian. So which language has the longest word? Let the games begin!

what's the longest word in the world finger on globe

German – Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz

Wow! That’s a massive 63 letters long. It means “law for regulating the labeling of beef.” This hyper word won German Word of the Year in 1999. But in 2013, the EU dropped requirements for beef labeling, and Germany dropped this word! But fear not, Germany still has some super-long words.

“Rechtsschutzversicherungsgesellschaften” is one of Germany’s longest words in common usage. This one means “legal protection insurance companies,” and has 39 letters. We all know how much Germans love the law and technical terms, so you might actually hear this one!

German numbers can get pretty long too. Unlike English numbers, German compounds numbers together. So the number 7,777 is written in word form in German as siebentausendsiebenhundertsiebundsiebzig. Gesundheit!

Dutch – Meervoudigepersoonlijkheidsstoornissen

The Dutch word for “multiple personality disorders” has a huge 38 letters. It may not be the longest word in the world, but that’s quite a mouthful for an everyday word. Like other Germanic languages, Dutch has a lot of compound words. This means that its vocabulary can be glued together to make long words, which are often phrases in themselves.

Spanish – Esternocleidooccipitomastoideos

This 31-letter word is one of the longest words in Spanish, meaning “sternocleidomastoid.” (That’s a muscle in the human neck.) It doesn’t quite compete with the longest German words, but this one really is a tongue twister.

Italian – Precipitevolissimevolmente

At 26 letters, this Italian word means “in a hurry,” or “hastily.” Such a long word for such a quick concept! This might be one of the longest Italian words to be officially recognized, but you will hear it more in jokes than in everyday language.

French – Anticonstitutionellement

The French word for “anticonstitutionally” has 25 letters in total. Not much competition for the longest German word, right?

Actually, some people think that intergouvernementalisations is the longest French word in common usage. This 27-letter word is used in administrative literature and means multiple governments working together. But the Académie Française has confirmed that this is not the longest word in the French language. They say it doesn’t count because it’s a neologism, meaning that it is a new word. So that breaks rule number 2: sustained usage! Maybe someday it will qualify as the longest word in French

You might have thought that French numbers would be extra long too, just like in German. French is be famous for having complicated numbers, such as quatre-vingt-dix (four-twenties-ten) for the number ninety. But luckily, they hyphenate their numbers, so no complex long numbers here!

Other Languages’ Longest Words (and Weirdest Words!)

A lot of other agglutinative languages have some super long words. But are they the longest words in the world?

Icelandic – Vaðlaheiðarvegavinnuverkfærageymsluskúraútidyralyklakippuhringur

That’s a gigantic 64-letter word! So is the longest word in the world an Icelandic one? This word means “a keychain ring for the outdoor key to a road worker’s shed in a moor called Vaðlaheið.” Can you see yourself using that in conversation? Perhaps not. So really this word isn’t in common usage. Sorry Iceland, try again next time!

Welsh – Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch

Welsh is well-known as a tricky language. Those double “L”s make a weird and wonderful sound, pronounced as a /ɬ/ (look it up in the International Phonetic Alphabet for more info), which has no English equivalent. It’s a bit like a “hl” sound. Try it – it’s harder than it seems! Let’s make this a bit easier. Say the word “house.” That’s a normal “h” sound. Now say the word “hue.” That’s a voiceless palatal fricative, which is a fancy way of saying that your tongue touches the roof of your mouth and pushes vibrating air through a tiny hole when you say it.

This 51-letter word might not be easy to say, but unfortunately it’s not really a word either. It’s the name of a town in Wales, in other words, a proper noun, so it doesn’t qualify. If you want to hear how this long Welsh word sounds, you can listen to Naomi Watts pronouncing the longest word perfectly on YouTube.

Danish – Gedebukkebensoverogundergeneralkrigskommandersergenten

Ah, Danish. The mother tongue of those silver-fox actors, Mads and Lars Mikkelsen. This 54-letter word was invented by another famous Danish native, fairytale author Hans Christian Andersen. It means “the goaty-legged-above-and-under-general-war-commanding-sergeant.” Yes, really! He invented this word to make fun of traditional Danish military titles. But as you’ll know by now, that means it’s not in common usage, and it’s not really meaningful. So once again, this is not really eligible for the contest of the longest word in the world.

Hans Christian Andersen Statue, inventor of the longest word in Danish

I bet you think you’ve seen it all now! German beef labeling, Italian inside jokes, Danish fairytales, and Welsh tongue-twisting towns. The longest words in the world really are the weirdest ones. How about a little bit of relief from those long words?

Take a Break! The Shortest Longest Words

Longest Words with One Syllable

  • Strengths (9 letters)
  • Scrounged (9 letters)
  • Schlepped (9 letters)
  • Screeched (9 letters)
  • Slapped (8 letters)
  • Scratched (9 letters)
  • Scrunched (9 letters)

Seems like those S-words might all have something in common! These are all words that only have one syllable. We s-s-s-s-struggled to come up with any that didn’t start with S. Can you? If you’ve thought of a long word with only one syllable, let us know in the comments!

Longest Words with No Vowels

We all know that it’s rare to find a word without a vowel. Unless of course you’re speaking Welsh! Here are some of the longest English words without any vowels:

  • Rhythms (7 letters)
  • Spryly (6 letters) – this means to act quickly.
  • Syzygy (6 letters) – we hadn’t heard of this one either! It has a few meanings, including a straight line of three or more celestial bodies in astronomy.

We know what you’re thinking. Doesn’t “y” sometimes count as a vowel? Here are some words without it:

  • Tsktsk – the accepted spelling of the sound of disapproval
  • nth – the mathematical term for “the item at position n in a sequence.”

Winner of the Longest Word in the World

Now that we’ve jumped all the technical hurdles and crossed the globe to find the longest words in history, it’s time for the verdict. We’ve seen so many long words, we think that some deserve an honorable mention!

The World’s Longest Technical Word

As we saw at the start of our hunt, the longest word according to a lot of sources is the technical name for the protein titin. It is the same across all languages, and has nearly 200,000 letters. Here’s a snippet of the first 4,000 characters!

Chemical Name of Titin, the world's longest technical word

Definitely not a word for the faint of heart! But as we know, lots of people discount this as a technical term which is never ever used.

The Longest Coined Word

The longest coined or made-up word is a difficult one to judge. If we include agglutinative languages, we’d be here for years just trying to imagine them all. For example, Polish allows the phrase “999,999,999,999 years old” to be glued together into one word. And it ends up being 176 letters long! So “dziewięćsetdziewięćdziesiątdziewięćmiliardówdziewięćsetdziewięćdziesiątdziewięćmilionówdziewięćsetdziewięćdziesiątdziewięćtysięcydziewięćsetdziewięćdziesięciodziewięcioletniego” might have to be discounted. You might be here until you’re 999,999 million years old if you try to count all the agglutinative words!

In the annual meeting of the National Puzzlers’ League in 1935, the league’s president Everett M. Smith decided to challenge the world’s longest words. He came up with pneumono­ultra­microscopic­silico­volcano­coniosis. This 45-letter word now appears in the Oxford English Dictionary as “an artificial long word said to mean a lung disease caused by inhaling very fine ash and sand dust.” It overtook “electrophotomicrographically” at the longest word to appear in any English dictionary, even if it is a fake!

The Longest Common Word in any Language

So here it is, the longest common word in any language! And by that, we mean one you’re likely to hear or use in that language. As we saw earlier, Germany boasts a huge 63-letter word which used to be used commonly in the meat packing industry, but we aren’t quite convinced. So our winner for the longest word in common usage is… drumroll please!

The Dutch! Their 38-letter word for multiple personality disorders is probably one of the longest words you’re likely to hear in everyday conversation. “Meervoudigepersoonlijkheidsstoornissen” is such a long word that most people shorten it to MPS, and we don’t blame them! Click the play button to learn how to say the longest word in the world:

Give it a try!
The Netherlands, home to the longest word in the world


So now you know! Not only are the Netherlands home to delicious Stroopwaffels and winding canals, but they have the longest commonly used word in the world! Want to keep up with interesting language facts, tips, and tricks? Check out the MosaLingua InstagramFacebook, and YouTube channel for more! Don’t forget to leave us a comment below and let us know what you thought.