What's the Longest Word in English? So, Funny Story...

longest word in English crossword — The longest word in the English language (that's it above) was probably made up by a guy named Everett K. Smith, who was a big fan of crossword puzzles. Vector FX/Shutterstock/HowStuffWorks

It's the kind of random thought that pops into your head in while typing a long word that you never get right on the first try: What is the longest word in English? You know it can't be the one that you're struggling to type, so what is it?

The Longest Word: A Bit of Invention

It would be truly shocking if you were trying to type the longest word found in English language dictionaries, as it isn't really a word anyone uses. At all. The word is: "pneumonoultramicroscopicsilicovolcanoconiosis."

It's pronounced noo-muh-now-uhl-truh-mai-kruh-skaa-puhk-si-luh-kow-vaal-kay-now-kow-nee-ow-suhs. Just try saying that out loud.

According to Merriam-Webster, those 45 letters creating 19 syllables mean "a lung disease caused by the inhalation of very fine silicate or quartz dust and occurring especially in miners."

But here's the thing: While it's a real word, it's not a term anyone — even doctors — use to describe the actual condition. The word was likely made up by Everett K. Smith in the 1930s, when he was president of the National Puzzlers League. This was a group that loved crosswords and, by extension, words themselves.

Silicosis: The Actual Condition

Smith intended to create the longest word by mimicking medical terminology, even if there was already a recognized inflammatory lung disease to attach the word to. He just kind of made up the entire thing as a fun challenge.

In medical terminology, the word Smith coined refers to a lung disease called silicosis, or more colloquially, miner's lung. It's a decidedly un-fun condition.

Breaking it Down: The Longest Word In English

The English language is an especially complex one, made up of lots of different current and earlier languages. When you understand etymology, or the study of how words are formed, you can go pretty far in making up words.

Let's break down the longest word you'll find in an English dictionary, just to see where all those syllables came from.

Pneumo: This portion comes from Greek roots and refers to the lungs.
Ultra: This prefix comes from Latin and means "beyond."
Microscopic: You probably already know this one, which combines "mono," another Greek derivation, with "scope," which has Latin roots by way of Greek.
Silico: This refers to the element silicon, commonly found in sand. Like many Latin terms that made their way into English, it has many applications.
Volcano: This is of course the name for a mountain crater or hill that is formed from the eruption of lava, rock, gas, vapor, or other emanations from deep within the earth.
Osis: Now we're back with Greek, denoting a process or condition. Silicosis, as noted above, is the more common medical term for the condition that Smith re-dubbed.

Most Commonly Guessed 'Longest Word'

Although not quite as long as the previous entry "supercalifragilisticexpialidocious" is a common contender for one of the longest words in English.

Sometimes people assume this is the longest English word, since they're familiar with the song and the movie in which it appears: "Mary Poppins." It's a nonsensical word without a fixed meaning, although it seems to denote wonder or excitement.

Long Words Are Often Technical Terms

Many of the longest words in English do describe real medical conditions. Take "pseudopseudohypoparathyroidism," a technical term for an inherited disorder that results in short stature and a round face.

Outside the medical world, we have long words like "antidisestablishmentarianism." This word refers to someone who was opposed to the disestablishment of the Church of England. Sure, it's not a word we use a lot today, but it was used quite a bit at the end of the 19th century.

Longest Words in Special Categories

If you want to break it down further (and who doesn't?), you can grant distinction to the longest words that conform to specific criteria.

Some record-setting words are the longest within particular parameters. "Uncopyrightable," which refers to any work that cannot be copyrighted, is the longest word in English without any repeating letters. Words like this are called "isograms."
Then there's the longest word made of only vowels "euouae," which is a term that comes from medieval music.
On the other hand, you have the longest word without any vowels, "tsktsk." You probably know this one. It's an onomatopoeia (another great long word!) for the sound you make when someone or something disappoints you.
When it comes to the longest one-syllable word, there's some disagreement. "Squirrelled," at 11 letters long, is the winner, but you have to pronounce it as one syllable, which some people do. (You also have to spell it in the UK manner, as the North American spelling only uses one "l.") Another contender is "schmaltzed," having 10 letters.
Finally, you know there's got to be a word to describe someone who makes a habit of using long words. Surprisingly, it's only kind of long itself: "sesquipedalian."