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8 of the Longest Words in English

Do you have three and a half hours to spare?

The longest word in the English language contains 189,891 letters. It takes about three and a half hours to pronounce this technical name of the protein Titin. If you’re up for it, you can read and try to pronounce the word here.

You won’t hear this absurdly long word in a spelling bee or find it in a dictionary (it would take up 12 full pages). But there are other long English words that are commonly used. Many of these words are still technical or scientific terms, but take only a few seconds, rather than hours, to pronounce.

So if you want to prepare for your next trivia night, scrabble match, or just expand your vocabulary, keep reading. In this post, we will look at eight of the longest words in the English language.


Since most dictionaries omit the technical name of Tintin, this 45-letter word is generally considered the actual longest word in English. Yes, it is another technical term that you probably won’t use in daily conversation. But, pneumonoultramicroscopicsilicovolcanoconiosis is spoken by medical professionals when describing a specific lung disease caused by inhalation of silica or quartz dust.

Definition: Disease of the lung caused by inhaling fine silica or quartz particles.

Letters: 45

Origins: The origins of this word are unclear, but some sources say it was invented simply to be the longest English word.


Is it ironic that this word means “the habit of estimating something as worthless”? Maybe. Floccinaucinihilipilification isn’t used very often, if at all. Try sprinkling it into your daily conversations. You might impress (or really confuse) your friends.

Definition: The habit of estimating something as worthless

Letters: 29

Origins: This word originated in the mid-18th century and combines Latin and Greek elements.


This might be the first word on this list that you will use in casual conversation. This 19-letter word means “the fact of being impossible to understand.”

Definition: Impossible to understand

Letters: 19

Origins: Incomprehensibility stems from a Middle English word and contains Latin roots.


Back to the technical terms. Trichotillomania is the name of the phenomenon where people have an unexplained desire to pull out their own hair, eyelashes, and eyebrows.

Definition: Unexplained compulsion to pull out one’s own hair.

Letters: 16

Origins: Trichotillomania was first used by a French dermatologist in the 20th century.


Although it might sound like a science-fiction term, xenotransplantation is being studied in 21st-century medicine. This term describes the process of transplanting an organ from one species to a different species.

Definition: Cross-transplantation of organs between different species.

Letters: 19

Origins: This term was first coined in 1969.


Looking for a word to describe someone who avoids making a clear-cut statement? Try tergiversation. This term dates to the 1500s so, unfortunately, some humans have tried to evade telling the truth for hundreds of years.

Definition: Evasion of a clear-cut statement.
Letters: 14

Origins: This 16th-century word combines the Larin word tergiversate (to show reluctance), tergum (back) and versare (to turn).


This word is pretty straightforward, it simply means “not able or allowed to be protected by copyright.” Take a closer look at the word and you will realize each letter only appears once, making it one of the longest isograms in English.

Definition: Not able to be protected by copyright

Letters: 15

Origins: The Old English prefix un- was added to the word copyrightable to form this word. It first appeared around the 1920s, presumably when copyright laws were being established.


Hopefully, you’ve enjoyed learning these long words. If not, you might be facing a case of hippopotomonstrosesquippedaliophobia. Did you figure out what it means? Yes, this 36-letter word means the “fear of long words.”

Definition: Fear of long words

Letters: 36

Origins: This technical term was formed by adding Latin prefixes to the root -phobia (fear).

Interested in more language analysis? Check out 12 Amazing Palindromes from around the world.

ALTA offers several language services, including translation, interpretation, language testing, and language training. For more information, please contact us.

Stephanie Brown is a New York City-based travel blogger and freelance content creator. You can find her at The Adventuring Millennial.

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