Have you ever come across long English words that leave you tongue-tied?
Think of the kind that makes you pause and take a moment or more to pronounce these words.
With around 273,000 headwords — for example, if you look up the word “cat” in a dictionary, “cat” is the headword — in the second edition of the Oxford English Dictionary, but only 171,476 of them being in current use, we can’t help but wonder: what are the longest words in English?
Many of the longest words in the dictionary refer to medicine or chemistry.
The nature of their work, or science in general, calls for it as it deals with very specific things. They need special words to describe tiny details without leaving anything behind.
That’s why you get the longest words in English like “Methionylthreonylthreonylglutaminylarginyl…isoleucine”, which refers to the chemical name for the largest protein found in humans.
It has a staggering 189,819 letters and has not been included in the English dictionary as it would take up over 50 pages.
Due to its length, some have argued that it is not even a word — though the scientists will beg to differ.
Longest one-syllable word in English
When it comes to the longest one-syllable word in English, these words are surprisingly long for one-syllable words.
One example is “screeched,” a verb meaning “made a loud, squealing noise.” Here are some other long one-syllable words:
- Scratched
- Scrunched
- Stretched
- Straights
- Strengths
Other notable English words
Some of the longest words in English without vowels are:
- Twyndyllyngs: A 12-letter word of Welsh origin, meaning twins
- Symphysy: A 9-letter word that means a fusion of two bodies or parts
- Rhythms: A 7-letter word defined as repeated patterns of sounds
On the other hand, “euouae,” a 6-letter word meaning a type of cadence in medieval music, holds the Guinness World Records for being the longest word in English without consonants and for having the most consecutive vowels of any word.
The real challenge for international students — and sometimes even local ones — comes with spelling names that don’t appear the way they’re pronounced.
See: “Sean,” which is pronounced and easily mistaken for “Shaun”) or “Arkansas,” pronounced as ar-can-saw instead of the commonly mispronounced ar-Kansas, like its neighbouring state.
And since we’re going down this rabbit hole now, here are some of the longest words in English for the names of places:
@cosybadgeradventures After years of wanting to check this place off my list, I finally made it to the longest place name in the world! #newzealand #nz #workingholiday #workingholidaynz #nzworkingholiday #roadtrip #winterroadtrip #nzroadtrip #roadtripnz #vanlife #vanlifenz #vanlifenewzealand #freedomcamping #freedomcampingnz #taumata #placenames #longestplacename #longestplacenameintheworld ♬ original sound – Just2maori
1. Taumatawhakatangihangakoauauotamateaturipukakapikimaungahoronukupokaiwhenuakitanatahu: 85 letters which can be shortened to Taumata, this hill in New Zealand is named in the Māori language and translates to “the summit where Tamatea, the man with the big knees, the climber of mountains, the land-swallower who travelled about, played his nose flute to his loved one.”
2. Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch: 58 letters which can be shortened into Llanfair PG, Llanfairpwll, Llanfairpwllgwyngyll (which still has 20 letters), this village on an isle in Wales means “the church of St Mary at the pool of the white hazels near the fierce whirlpool and the church of St Tysilio of the red cave” in Welsh.
3. Chargoggagoggmanchauggagoggchaubunagungamaugg: 45 letters which can be shortened to Lake Chaubunagungamaug, or the much more common Webster Lake. Located in Massachusetts, US, the name of the lake comes from the language of the Nipmuc people who lived in the area. It is believed that a local newspaper editor translated it into “You fish on your side; I fish on my side; nobody fishes in the middle” — and this translation has caught on to today.
An honourable mention goes to Thailand’s capital city, Bangkok, which holds the Guinness World Record for the longest city name in the world.
It is pronounced along the lines of Krung Thep Mahanakhon Amon Rattanakosin Mahinthara Ayuthaya Mahadilok Phop Noppharat Ratchathani Burirom Udomratchaniwet Mahasathan Amon Piman Awatan Sathit Sakkathattiya Witsanukam Prasit.
This translates into “the city of angels, the great city, the eternal jewel city, the impregnable city of God Indra, the grand capital of the world endowed with nine precious gems, the happy city, abounding in an enormous Royal Palace that resembles the heavenly abode where reigns the reincarnated god, a city given by Indra and built by Vishnukarma.”
13 longest words in English that will test your memory
The longest word in English refers to a medical condition commonly known as “black lung.” Source: AFP
1. Pneumonoultramicroscopicsilicovolcanoconiosis
This word is known for being one of the world’s longest words in English. This 45-letter word refers to a lung disease that is caused by the inhalation of silica or quartz dust.
It was coined in 1935 by the then-president of the National Puzzlers’ League, Everett M. Smith.
While the word is made up, the disease is real and it’s known under the names pneumoconiosis, silicosis, or black lung.
It can be broken down into:
- Pneumono: from ancient Greek, which means lungs
- ultra: from Latin, meaning beyond
- micro and scopic: from ancient Greek, meaning small looking, referring to the fineness of particulates
- silico-: from Latin, silicon
- volcano: from Latin, referring to volcano
- coni: from ancient Greek, which means dust
- -osis: from ancient Greek, suffix to indicate a medical condition
2. Hippopotomonstrosesquippedaliophobia
At 36 letters, hippopotomonstrosesquippedaliophobia is the second longest word in English. The irony is that it is one of the longest words in English and refers to the phobia or fear of long words.
Since the word is so long and may scare a few, many have coined a simpler term known as sesquipedalophobia.
However, this fear isn’t actually recognised by the American Psychiatric Association. It is considered to be a social phobia. In the US, specific phobias, such as the fear of long words, affect between 3 to 15% of the population.
The word can be broken down into:
- Sesqui derives from Latin and refers to one and a half, and the phrase “sesquipedalia verba” was used long ago by the Roman poet Horace to criticise writers who used the words “a foot and a half long”
- Hippopotamine refers to “something very large”
- The word “monstr” is the Latin origin of a ‘monstrous being’ or something that is huge or terrifying

Supercalifragilisticexpialidocious became popular because of the film Mary Poppins. Source: AFP
3. Supercalifragilisticexpialidocious
Coming in third on the list of longest words in English is supercalifragilisticexpialidocious.
At 34 letters, this word became popular from the 1964 musical film “Mary Poppins.” This mouthful of nonsensical syllables has brought cheer to audiences for many years.
In the film, it is described as the word to use ” when you have nothing to say.” According to the Oxford English Dictionary, the word has now come to mean an expression of excitement or ” wonderful.”
It can also be commonly used as a shortened adjective, supercalifragilistic or as an adverb supercalifragilistically.
Many dictionaries have since recognised it, but not all.
The word is made up of the following root words:
- Super: above
- Cali: beauty
- Fragilistic: delicate
- Expiali: to atone
- Docious: educable
4. Pseudopseudohypoparathyroidism
Pseudopseudohypoparathyroidism is a medical term that refers to a relatively mild form of pseudohypoparathyroidism.
This 30-letter word is the only word in the dictionary with a repetition of the word pseudo. It was named for its similarity to pseudohypoparathyroidism.
5. Eellogofusciouhipoppokunurious
Another 30-letter word to keep up your sleeves is eellogofusciouhipoppokunurious, an American slang meaning “very good, very fine.”
It is a nonce — which means it is a word made up for the occasion. It’s also believed that the slang originated from Nebraska, Oregon, and Massachusetts.

Luckily, most of us will never have to use any of these longest words in English for any part of our lives. Source: AFP
6. Floccinaucinihilipilification
Floccinaucinihilipilification is the act of regarding something as unimportant or as worthless. It is commonly used in a humorous way.
Ironically, floccinaucinihilipilification is a pretty valueless word itself; it’s almost never used except as an example of a long word.
This 29-letter word consists of a series of Latin words (flocci, nauci, nihili, and pili), all signifying “at a small price” or “for nothing,”
The first recorded use is by William Shenstone in a letter in 1741: “I loved him for nothing so much as his flocci-nauci-nihili-pili-fication of money”.
7. Antidisestablishmentarianism
The word antidisestablishmentarianism, with 28 letters and 12 syllables, is one of the longest words in English.
It originated in 19th-century Britain when a political movement sought to separate church and state. The opposition wanted to disestablish the Church of England in Ireland, Scotland and Wales.
The original meaning of the word was applied to those who supported this movement. Today, the word is rarely used but means to be against the establishment of any state religion.
8. Spectrophotofluorometrically
Another one of the longest words in English, this time with 28 characters, is the adverb of a spectrophotofluorometre — a tool used to assess the amount of light given off by something.
While you might think you’ll never have to come across this word, it’s more common than you think. Various fields use it, from pharmaceutical companies to textile manufacturing and from agriculture to the food and beverage industry.
One way to use the word is as follows: “The sample was assessed spectrophotofluorometrically.”

One of the longest words in English comes from William Shakespeare’s works. Source: AFP
9. Honorificabilitudinitatibus
At 27 letters, it is the longest word in the English language that alternates between consonants and vowels.
Deriving from Latin, it means honourable, honourableness or “the state of being able to achieve honours.”
This word has only appeared once, appearing in Shakespeare’s works. It was used mockingly in “Love’s Labour’s Lost” to insult people who like to use big words.
10. Psychoneuroendocrinological
Another word with 27 letters is psychoneuroendocrinological, the adjective to psychoneuroendocrinology. As you might be able to tell, this word comprises the three fields of science: psychology, neurology, and endocrinology.
This particular field examines the relationship between the brain, mind, and hormones. Often shorted to PNE, it’s a clinical field studying how hormone levels fluctuate and how these fluctuations relate to human behaviour.
11. Thyroparathyroidectomised
Thyroparathyroidectomised is another medical term on this list. It is one of the longest words in English, with 25 letters.
This medical term refers to the surgical removal of both the thyroid and parathyroid glands.

One of the longest words in English was invented while looking for gas to be used as a refrigerant. Source: AFP
12. Dichlorodifluoromethane
This 23-letter-long word came about as three companies in the US were searching for a nonflammable, nontoxic alternative to ammonia and sulfur dioxide to use as a refrigerant.
In the 1920s, a researcher, Thomas Midgley, discovered a colourless gas now known as dichlorodifluoromethane.
13. Incomprehensibilities
At 21 letters long, incomprehensibilities is the tenth longest word in English. In the 1990s, it set the record as the longest word “in common usage” – which seems almost incomprehensible.
It refers to the state of being impossible or extremely difficult to understand and comes from the Latin word “incomprehensibilis.”
Here’s how you can use incomprehensibilities in a sentence: The incomprehensibilities of my friends are beyond me.
Disclaimer: This article was last updated on January 21, 2025.