15 of the longest words in English and how to pronounce them

Are you feeling supercalifragilisticexpialidocious whenever you learn new English words? If so, you’re going to have a blast because we’re about to share with you the longest words in the English language.

Even though you’ll be met with some people’s floccinaucinihilipilification of your new vocabulary, knowing these words will make you sound more eloquent and knowledgeable in the English language!

So, are you ready to discover the longest words in the English language? Let’s dive right into this unusual and fun article.

The longest English word

The longest word in English has 189,819 letters and takes 3 hours to pronounce. This is a technical term for the chemical composition of titin. Titin is the largest known protein responsible for maintaining the passive elasticity of the muscles.

The reason why this word is so long is that titin is formed by 244 individual protein domains, which are connected into one sequence. Now, imagine 244 names of chemical compounds squashed together into one word.

We’ll show you a glimpse:


If you’d like to see the entire word, check it out here. We’re warning you, though. It looks like a string of letters your cat accidentally wrote when it sat on your keyboard.

The longest word in the English language dictionary

While the monstrosity of the word we mentioned above is, indeed, the longest word in English, it’s disputed whether it’s even a word - which is why it’s not recorded in any English dictionary.

In that case, what’s the longest word in the English language dictionary? It’s pneumonoultramicroscopicsilicovolcanoconiosis.

Pneumonoultramicroscopicsilicovolcanoconiosis meaning

The funny thing about pneumonoultramicroscopicsilicovolcanoconiosis is that it’s not even a real word! It’s an invented term that was coined by Everett M. Smith, the president of the National Puzzlers’ League. Everett came up with this word as a sarcastic term for long medical terms and a synonym for silicosis - a lung disease caused by inhaling sand and ash dust.

Pneumonoultramicroscopicsilicovolcanoconiosis is a string of Latin terms that together describe an inflammatory lung disease caused by long-term inhalation of silica dust. While the word is made up, the disease is real, and it’s known under the names pneumoconiosis, silicosis, or black lung in the UK.

How to pronounce the longest word in English

Are you wondering how to pronounce this incredibly long word? Let’s dissect it:

Pneumono-A prefix meaning “lung”
MicroscopicVery tiny; seen only with a microscope
SilicaA dioxide of silicon that occurs as quartz sand
VolcanoA vent in the earth’s crust or a mountain crater where lava is expelled
PneumonoconiosisA lung disease

In case you still need it, here’s the phonetic respelling:


And here’s this term again, written phonetically: / ˈnu mə noʊˌʌl trəˌmaɪ krəˌskɒp ɪkˈsɪl ɪˌkoʊ vɒlˌkeɪ noʊˌkoʊ niˈoʊ sɪs, ˈnyu- /

15 of the longest words in English

We hope that you don’t have hippopotomonstrosesquippedaliophobia because we’re about to share with you 15 of the longest words in the English language.

While most of them are technical terms, you’ll probably find a way to use “floccinaucinihilipilification” or “xenotransplantation” in a conversation.

Dick Van Dyke sings Supercalifragilisticexpialidocious in the Mary Poppins movie. Could it be the longest word in English?

WordMeaningLetter count
PneumonoultramicroscopicsilicovolcanoconiosisA specific lung disease caused by inhaling quartz dust.45
HippopotomonstrosesquippedaliophobiaA fear of long words.36
PseudopseudohypoparathyroidismA medical condition of the thyroid30
SupercalifragilisticexpialidociousAn expression of excitement.34
EellogofusciouhipoppokunuriousVery good, very fine30
FloccinaucinihilipilificationEstimating something as worthless29
AntidisestablishmentarianismOpposition to the disestablishment of the Church of England28
HonorificabilitudinitatibusThe state of being able to achieve honors27
ThyroparathyroidectomizedA medical term that describes the excision of the thyroid and parathyroid glands.25
DichlorodifluoromethaneA chlorofluoromethane CF2Cl223
XenotransplantationThe process of transplanting organs from one species to another19
IncomprehensibilitiesThings that are impossible to comprehend21
TrichotillomaniaAn inexplicable desire to pull your own hair16
UncopyrightableImpossible to be protected by copyrights15
TergiversationWhen someone avoids making a clear statement14

What’s the longest one-syllable word in English?

The majority of the longest words in the English language are technical or medical terms formed by a string of individual parts. But there are also some unusually long words that only have one syllable. Curious to find out what they are?

The most commonly cited one-syllable English word is the verb screeched, which means “made a loud, squealing noise.” But there are also other one-syllable words mentioned in the English dictionary, all with 9 letters. These are:

  • Schlepped
  • Scratched
  • Scrounged
  • Scrunched
  • Stretched
  • Straights
  • Strengths

But, there’s another word that takes away the crown of the longest monosyllabic word in the English language with 12 letters: schtroumpfed. The problem with this word, however, is that it’s not a real word. It originates from the French word for… Smurfs, “Schtroumpfs.” It’s being debated whether this word should even be in the English dictionary.

What is the longest English word without vowels?

If you’re wondering what’s the longest English word without vowels, we’re sorry to say that there’s no clear answer. The answer depends on whether we consider the “y” to be a consonant or a vowel. In most English words, though, y is a vowel.

Here’s the list of the longest words without vowels but including y:

TwyndyllyngsThe word of Welsh origins, meaning twins
SymphysyA fusion of two bodies or parts
RhythmsRepeated patterns of sounds
SprylyAn adverb from the adjective “spry”
SyzygyAn alignment of planets in astrology
CryptsPlaces where people are buried
TrystsClandestine or secret meetings

What’s the longest palindrome word?

Even if you had no idea what a palindrome is, we bet you use these words in your everyday conversations without realizing it. Words such as mom, level, or noon are all palindromes. The common denominator? They all read the same forward and backward.

But what’s the longest palindrome word in English? Well, it’s a word invented by James Joyce to describe the sound of the knock on the door: tattarrattat.

The longest place names in the English-speaking countries

Have you ever been to Taumatawhakatangi­hangakoauauotamatea­turipukakapikimaunga­horonukupokaiwhen­uakitanatahu? Or Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch? While these words look as if you fell asleep on the keyboard, these are actually names of places you can visit.

PlaceLocationLetter Count
Taumatawhakatangi­hangakoauauotamatea­turipukakapikimaunga­horonukupokaiwhen­uakitanatahuA hill in southern Hawke’s Bay in New Zealand85
LlanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochA name of a town in Wales58
ChargoggagoggmanchauggauggagoggchaubunagungamauggA lake on the border of Connecticut and Massachusetts, USA45
TweebuffelsmeteenskootmorsdoodgeskietfonteinA farm located about 200km west from Pretoria in South Africa44
PekwachnamaykoskwaskwaypinwanikA lake in Manitoba, Canada31
MamungkukumpurangkuntjunyaA hill in South Australia, approximately 108km away from a town called Marla26
BullaunancheathrairaluinnA name of a town in Ireland25
NunathloogagamiutbingoiA name of a beach on the southwestern coast of Alaska, USA23

Learn to pronounce the longest English words

While the words mentioned in this article seem absolutely unpronounceable, some people have the superpower of pronouncing them without a drop of effort. Here are a few videos we’ve found of incredibly talented people pronouncing these monstrous words.

Liam Dutton nails pronouncing Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch

Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch just rolls off the tongue of this weatherman:

7 year child spelt out the LONGEST WORD IN ENGLISH | Brilliant

Spelling the word pneumonoultramicroscopicsilicovolcanoconiosis is as easy as ABC to this 7-year old kid:

Reading The Longest English Word (190,000 Characters)

Reading the longest word in English takes this YouTuber 2 hours. Let’s admire this guy’s insane patience!

You’re ready for honorificabilitudinitatibus

Now that you know the longest words in the English language, there are no incomprehensibilities left. You’re ready to impress your friends with your incredible knowledge of the English language and its nuances.

These words may not come in handy anytime soon unless you’re planning to visit Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch or diagnose someone with a pneumonoultramicroscopicsilicovolcanoconiosis. But still, we bet you had fun learning these words with us. For more fun challenges, we've also compiled 252 of the hardest English words to pronounce and spell here.

And if you’d like to learn some more (useful) English words, check out the other articles on our English blog.

Expand your knowledge of English


Learn with Berlitz

Call Us


Find out more

Fill in the form below and we’ll contact you to discuss your learning options and answer any questions you may have.