23 Long Words | Meanings, Letter Counts & Examples
Some languages, like German, Finnish, or Turkish, are famous for their long words. English isn’t usually one of them, but that doesn’t mean it doesn’t have long words worth learning.
Have you ever known someone with hippopotomonstrosesquipedaliophobia? Do you know the more common way to say laryngotracheobronchitis? Or maybe you use subcompartmentalization when organizing your closets?
This article contains a list of long words—including the longest word in English—what they mean, and how to use them.
What is the longest word in the world?
The longest word in the world depends on how you define a “word.”
If including technical terms, the longest word in the world is the chemical name for titin, the largest known protein. It has 189,819 letters, beginning with “methionylthreonylthreonyl…” and ending with “…isoleucine.” This word allegedly takes around three hours to pronounce.
If going off of what major dictionaries consider words, the longest word in the world is pneumonoultramicroscopicsilicovolcanoconiosis, a type of disease.
Keep in mind these are the longest words in the world in English. Another language may have even longer words than these!
Methionylglutaminylarginyltyrosylglutamyl … serine is the chemical name for E. coli. It has 1,909 letters and is the longest published word.
Lopadotemachoselachogaleokranioleipsano … pterygon is a fictional dish of food invented by the playwright Aristophanes. It’s a transliteration from Greek with 183 letters and is the longest word to appear in literature in English.
23 long words
Below are some of the longest words in English. Some are technical, scientific, or medical terms, some were invented by writers, and others came about naturally. Language is always evolving, so it’s possible that you may encounter new or unfamiliar words that aren’t yet included in your favorite dictionary.
1. Pneumonoultramicroscopicsilicovolcanoconiosis
How many letters: 45
Part of speech: noun
Meaning: a lung disease caused by inhaling fine ash and dust
Example: Miners who work in areas with high levels of dust may develop pneumonoultramicroscopicsilicovolcanoconiosis.
2. Hippopotomonstrosesquipedaliophobia
How many letters: 35
Part of speech: noun
Meaning: the fear of long words
Example: People with hippopotomonstrosesquipedaliophobia may feel distress or anxiety if they have to pronounce long words.
3. Supercalifragilisticexpialidocious
How many letters: 34
Part of speech: adjective
Meaning: filler for when you have nothing to say
Example: Mary Poppins said that supercalifragilisticexpialidocious sounds atrocious.
4. Eellogofusciouhipoppokunurious
How many letters: 30
Part of speech: adjective
Meaning: very good or very fine
Example: Donna felt eellogofusciouhipoppokunurious when she correctly pronounced the long word during the spelling bee.
5. Pseudopseudohypoparathyroidism
How many letters: 30
Part of speech: noun
Meaning: an inherited disorder that can cause symptoms including short stature, shortened bones, and obesity
Example: The doctor diagnosed Harry with pseudopseudohypoparathyroidism after reviewing his family history.
6. Floccinaucinihilipilification
How many letters: 29
Part of speech: noun
Meaning: the action of estimating something as worthless.
Example: Bob’s floccinaucinihilipilification of the project upset the team members who had worked hard on it.
7. Hexakosioihexekontahexaphobia
How many letters: 29
Part of speech: noun
Meaning: the fear of the number 666
Example: Mike’s hexakosioihexekontahexaphobia made him anxious every time he saw the number appear.
8. Antidisestablishmentarianism
How many letters: 28
Part of speech: noun
Meaning: opposition to the disestablishment of the Church of England.
Example: My mother believes in disestablishing the Church of England, but my father subscribes to antidisestablishmentarianism.
9. Spectrophotofluorometrically
How many letters: 28
Part of speech: adverb
Meaning: related to the measurement of the intensity of fluorescent light
Example: The samples were analyzed spectrophotofluorometrically to determine their concentrations.
10. Honorificabilitudinitatibus
How many letters: 27
Part of speech: noun
Meaning: the state of being able to achieve honors
Example: Dale’s honorificabilitudinitatibus was evident in the many awards he received throughout his career.
It appears in Shakespeare’s Love’s Labour’s Lost, making it the longest word ever used by the playwright.
11. Psychoneuroendocrinological
How many letters: 27
Part of speech: adjective
Meaning: of or related to the study of the study of the relationship between psychology, the nervous system, and the endocrine system
Example: The doctor’s psychoneuroendocrinological approach helped Laura understand the effects of stress on her hormone levels.
12. Hydrochlorofluorocarbons
How many letters: 24
Part of speech: noun
Meaning: chemical compounds containing carbon, hydrogen, chlorine, and fluorine (also known as “HCFCs”)
Example: The European Union is phasing out hydrochlorofluorocarbons, which are harmful to the ozone layer.
13. Laryngotracheobronchitis
How many letters: 24
Part of speech: noun
Meaning: a respiratory infection that leads to inflammation of the larynx, trachea, and bronchi
Example: The child was diagnosed with laryngotracheobronchitis after presenting symptoms of a severe cough.
14. Microspectrophotometries
How many letters: 24
Part of speech:
Meaning: measures of spectra in microscopic samples using different wavelengths of electromagnetic radiation
Example: Albert employed microspectrophotometries to analyze the pigments in the ancient manuscript.
15. Dichlorodifluoromethane
How many letters: 23
Part of speech: noun
Meaning: a colorless gas used as a refrigerant and aerosol propellant (also known as “Freon”)
Example: The production of dichlorodifluoromethane was banned due to its harmful effect on the environment.
16. Subcompartmentalization
How many letters: 23
Part of speech: noun
Meaning: the division of a larger compartment into smaller sub-compartments
Example: Subcompartmentalization has helped improve organization and efficiency in the company’s storage facilities.
17. Counterrevolutionaries
How many letters: 22
Part of speech: noun
Meaning: people who participate in a movement opposing a revolution
Example: The counterrevolutionaries plotted to regain power after the government was overthrown.
18. Deinstitutionalization
How many letters: 22
Part of speech: noun
Meaning: the process of moving individuals in mental institutions to community-focused support systems
Example: Deinstitutionalization changed the way mental health was approached in society.
19. Electroencephalography
How many letters: 22
Part of speech: noun
Meaning: a test that records the electrical activity of the brain
Example: The doctor ordered an electroencephalography to assess the patient’s brain activity.
- “Electro-” refers to “electricity”
- “Encephalo-” means “relating to the brain”
- “-graphy” denotes “the process of recording or writing”
20. Thyroparathyroidectomy
How many letters: 22
Part of speech: noun
Meaning: the surgical removal of the thyroid and parathyroid glands
Example: After Lucy’s diagnosis, the surgeon recommended a thyroparathyroidectomy to treat her condition.
21. Disproportionableness
How many letters: 21
Part of speech: noun
Meaning: the state of being out of proportion
Example: The disproportionableness of resources among the regions led to significant disparities in development.
QuillBot’s Paraphraser can help you find simpler options that mean the same as long words.
22. Psychoneuroimmunology
How many letters: 21
Part of speech: noun
Meaning: the study of the interaction between psychology, the nervous system, and the immune system
Example: Research in psychoneuroimmunology is revealing how stress affects immune responses.
23. Anthropomorphization
How many letters: 20
Part of speech: noun
Meaning: the attribution of human characteristics to non-human entities
Example: Anthropomorphization is a common literary device in children’s books because it makes animals and objects more relatable to young readers.
Common long words
Many of the words above are technical, scientific, or very specific. Here are some common long words you’re more likely to come across in everyday English.
| Word | Letters | Part of speech | Meaning |
|---|---|---|---|
| Compartmentalization | 20 | Noun | The division of something into sections or categories, often to stop those sections from mixing |
| Uncharacteristically | 20 | Adverb | In a way that is not usual for someone or something |
| Disproportionately | 18 | Adverb | In a way that is out of balance or not in proportion |
| Counterproductive | 17 | Adjective | Having the opposite of the desired effect |
| Interdisciplinary | 17 | Adjective | Involving more than one area of knowledge |
| Incomprehensible | 16 | Adjective | Impossible to understand |
| Hyperventilating | 16 | Verb | Breathing at an abnormally fast pace |
| Transcontinental | 16 | Adjective | Spanning a continent, especially when related to a railroad |
| Unconstitutional | 16 | Adjective | Not in agreement with a constitution (in American English, especially the U.S. Constitution) |
| Hypothetically | 14 | Adverb | In a way that is based on a theoretical situation rather than reality |
| Surreptitious | 13 | Adjective | Done secretly, especially because it would not be approved of |
| Misunderstand | 13 | Verb | To understand incorrectly |
Your dissertations must be interdisciplinary but balanced, without disproportionately favoring one discipline over the other.
Margaret won a Pulitzer Prize for her work revealing a surreptitious scheme by government officials to pass an unconstitutional law without public scrutiny.
Frequently asked questions about long words
- What is eellogofusciouhipoppokunurious?
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“Eellogofusciouhipoppokunurious” is a 30-letter adjective that means “very good or fine.” It’s one of the longest words in English.
For example, “The chef’s special dessert was nothing short of eellogofusciouhipoppokunurious—a truly delightful treat!”
This word supposedly developed as American English slang in the early 20th century, though it doesn’t appear in any major dictionary.
Use QuillBot’s free Paraphraser to find different ways to incorporate weird words like this one into your writing.
- What are some 15 letter words?
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Some 15-letter words are:
- Accomplishments
- Benzodiazepines
- Cyclohexylamine
- Discombobulated
- Disenfranchised
- Electromagnetic
- Excommunication
- Extrajudicially
- Intellectualism
- Juxtaglomerular
- Psychoanalyzing
- Quinquagenarian
- Revolutionizing
- Schizoaffective
- Unbelievability
When writing with long words, use QuillBot’s Grammar Checker to make sure you spell them correctly.
- How do you pronounce supercalifragilisticexpialidocious?
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You pronounce “supercalifragilisticexpialidocious” as “soo-per-ka-luh-fra-juh-lih-stuhk-ek-spee-ah-luh-doh-shuhs.”
If writing this word, use QuillBot’s Grammar Checker—which can check even long words like this one—to make sure you spell it correctly.
- What is the longest word in the world that takes 3 hours to say?
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The longest word in the world that takes 3 hours to say is the chemical name for the protein “titin.”
This word has 189,819 letters. The first 35 letters are “methionylthreonylthreonylglutaminyl” and the last 10 are “isoleucine.”
It takes around 3 hours to pronounce and when written, takes up over 100 pages.
Even if this word is too big to paste into QuillBot’s Grammar Checker, the tool can help you correctly spell other long words.
