stephaniewindle Last updated: September 18, 2023

The 15 Longest Words in the English Language (Plus 107 Other Shockingly Long Words)

The longest word in the English language is “pneumonoultramicroscopicsilicovolcanoconiosis.”

Try saying that quickly five times!

In this post we’ll explore some of the longest words in English, plus teach you how to break them down so that you can pronounce them easily.

Longest Word in English: Pneumonoultramicroscopicsilicovolcanoconiosis
More Long Words in English
Longest English Words Without Vowels
Longest English Word with One Syllable
Longest Medical English Words
Longest English Words with No Repeated Letters
Longest English Words with All 5 Vowels in Order
Longest Place Names in English
Longest Nouns in English
Longest Verbs in English
Longest Adjectives in English
Longest Suffixes in English
Longest Prefixes in English
How to Learn the Longest Words in English

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Longest Word in English: Pneumonoultramicroscopicsilicovolcanoconiosis

Letters: 45

Definition (noun): Lung disease caused by breathing in dust or volcanic ash

The patient is experiencing signs of pneumonoultramicroscopicsilicovolcanoconiosis after hiking near the site of a volcanic eruption.

This is the longest word that exists in the English language. As with other long words, you should be patient and break it down into its individual components.

As you can see below, knowing the parts of this word will be especially helpful for anyone studying English in an academic, scientific or medical environment.

Essential word parts: Pneumo- (lung), microscopic- (small), coni- (particles) and a suffix: -osis (often indicates a disease).

More Long Words in English

We will show you the essential parts of these long words that can help you learn the word itself and other English words. We will specifically note common English prefixes and suffixes to pay attention to.

Methionylthreonylthreonylglutaminylalanyl…isoleucine

Letters: 189,819

Definition (noun): Chemical composition of “titin,” which is the largest known protein in the body

This word has taken some people around 2-3.5 hours to pronounce! Amazing, isn’t it? It’s not, however, considered the longest word in English—because it’s not in a dictionary.

Essential word parts: Amino acid residues that make up the protein. These include methionine, threonine, glutamine, alanine and isoleucine.

Floccinaucinihilipilification

Letters: 29

Definition (noun): Deciding that something has no value

Since my wallet was becoming so huge, I took a few minutes for some floccinaucinihilipilification of all the old cards I was keeping in there.

This is one of those complex words that seems made up. It was formed from various Latin words and can still be confusing to understand after breaking it down.

Essential word part: Nihili- (nothing)

Incomprehensibility

Letters: 19

Definition (noun): Impossible to understand

The incomprehensibility of the word made people question its meaning.

This word has common prefixes and suffixes that you will see in many other English words. Plus, you may already be familiar with more basic forms of this word, such as incomprehensible (adjective — impossible to understand)

Essential word parts: include a prefix in- (not), a root word prehend (from the Latin for “grasp”) and a suffix: –ity (suffix used to form a noun out of an adjective).

Surreptitious

Letters: 13

Definition (adjective): Secret, stealthy

The robbers were surreptitious as they stole the jewels.

This word is used fairly regularly among native English speakers. It is one of the less complex long English words.

Essential word part: Prefix: sur- (under, below)

Uncharacteristically

Letters: 20

Definition (adverb): Not typical

The star basketball player uncharacteristically missed the game-winning shot.

Here is another fairly standard word that helps you practice both a common prefix and suffix.

Essential word parts: Prefix: un- (not) and a suffix: -ly (used to form an adjective)

Supercalifragilisticexpialidocious

Letters: 34

Definition (adjective): Especially wonderful

The sun is shining and all is right in the world. It is a supercalifragilisticexpialidocious day.

This is a made-up word that native English speakers recognize from the classic 1964 “Mary Poppins” movie (although a version of this word was invented even earlier).

Essential word parts: Cali- (beauty).

Subdermatoglyphic

Letters: 17

Definition (adjective): Pertaining to the layer of the skin beneath the fingertips

The subdermatoglyphic state of everyone’s fingerprints are different.

This word is extremely rare, and may be more interesting to linguists than to medical professionals. That is because it is a very long isogram, or a word that does not repeat any letters.

Essential word parts: Prefix: sub- (under, below — similar to “sur-“), derma- (skin) and a suffix: -ic (used to form an adjective).

Abstentious

Letters: 11

Definition (adjective): Self-restraining

You never have trouble sticking to your diet. You are so abstentious!

You will more commonly hear abstain, the verb form of this word. Abstain means to avoid or restrain yourself from something, like alcohol, online-shopping, food, etc.

Essential word parts: Suffix: -ious (used to form an adjective).

Uncopyrightable

Letters: 15

Definition (adjective): Not able to copyright a piece of artwork. If something is uncopyrightable, one person cannot prevent others from copying or distributing the art.

The idea was not original, so it was unfortunately uncopyrightable.

Un- and -able are common word parts. Try to memorize these and look for them in other English words.

Essential word parts: Prefix: un- (not) and a suffix: -able (ability).

Hippopotomonstrosesquipedaliophobia

Letters: 35

Definition (noun): Fear of long words

As she read this article, she realized that she had a severe case of hippopotomonstrosesquipedaliophobia.

This may be how you are feeling right now.

Essential word parts: Suffix: -phobia (fear).

Antidisestablishmentarianism

Letters: 28

Definition (noun): A political philosophy opposed to the disestablishment of the Church of England.

The word was used to describe a political movement in England in the 1800s. People supporting this movement were against a plan to separate the church from the state.

There were many supporters of antidisestablishmentarianism in Wales.

Essential word parts: Prefix: anti- (against) and dis- (opposite of), suffix: -arian (engaged in) and -ism (a belief in).

Honorificabilitudinitatibus

Letters: 27

Definition (noun): State of being able to achieve honors.

Dumbledore was well-known for lots of things, including being honorificabilitudinitatibus.

This rare Latin word features in William Shakespeare’s play “Love’s Labour’s Lost.”

Essential word parts: A root word honorificabilitudin (the state of being honorable) and suffix: –itatibus (a state of being).

Pseudopseudohypoparathyroidism

Letters: 28

Definition (noun): A rare inherited endocrine disorder that causes abnormal growth of bones.

She was diagnosed with pseudopseudohypoparathyroidism.

Essential word parts: Pseudo-(prefix) meaning false, hypo-(prefix) meaning below. Parathyroid- (root word) small glands in our body which regulate calcium and -ism (suffix) meaning “a belief in.”

Longest English Words Without Vowels

You need a vowel sound in order to pronounce a word! But while the following words do use vowel sounds, there are no vowels in their spelling.

Rhythms — the systematic arrangement of musical sounds according to duration and periodic stress (7 letters)
Syzygy — an alignment of three celestial objects, typically the sun, the earth and the moon (6 letters)
Flyby — a flight past a celestial body, especially by a spacecraft (5 letters)
Gypsy — a member of a traveling people with dark skin and hair who speak Romany and traditionally live by seasonal work and fortune-telling (5 letters)
Nymph — a mythological spirit of nature imagined as a beautiful maiden inhabiting rivers, woods or other locations (5 letters)
Crypt — a room or vault beneath a church, used as a chapel or burial place (5 letters)
Lymph — a colorless fluid containing white blood cells, which bathes the tissues and drains through the lymphatic system into the bloodstream (5 letters)
Tryst — a private romantic rendezvous between lovers (5 letters)

Longest English Word with One Syllable

There are no English words with only one syllable that are longer than nine letters. And most of these start with the letter “s,” though it’s unknown exactly why! Check them out below.

Strengths — the quality or state of being physically strong or capable (9 letters)
Scrunched — to crumple or squeeze into a compact shape or mass (9 letters)
Splurged — to spend extravagantly or indulgently (8 letters)
Screeched — to make a high-pitched, piercing sound (8 letters)
Scrounged — to obtain something without paying for it or by other means of persuasion (8 letters)
Scratched — to mark or damage the surface of something by scraping it with a sharp or rough object (8 letters)
Sprinkled — to scatter small drops or particles of a substance over an object or surface (8 letters)
Strength — the quality or state of being physically strong or capable (8 letters)
Stretched — to extend one’s body or a part of it to its full length (8 letters)

Longest Medical English Words

If you’ve ever tried to pronounce a disorder or a medical term, you may have noticed how long and complicated these words are. That’s because medical words are often taken from Greek and Latin and are extremely exact. After all, when you’re working in the medical profession, you need to be as clear and unambiguous as possible.

Psychoneuroendocrinological — relating to the interactions between psychology, neurology and endocrinology (27 letters)
Electroencephalographically — adverb form of electroencephalographic (27 letters)
Thyroparathyroidectomized — having had the thyroid gland and the parathyroid glands surgically removed (25 letters)
Laryngotracheobronchitis — inflammation of the larynx, trachea and bronchi, usually caused by a viral infection (25 letters)
Thyroparathyroidectomized — having had the thyroid gland and the parathyroid glands surgically removed (25 letters)
Immunoelectrophoretically — adverb form of immunoelectrophoretic (24 letters)
Electroencephalographic — relating to the measurement and interpretation of electrical activity in the brain (23 letters)
Otorhinolaryngological — relating to the study and treatment of diseases of the ear, nose and throat (23 letters)
Gastroenteroanastomosis — a surgical procedure to create a connection between the stomach and the intestine (22 letters)
Cardioencephalography — a technique for measuring electrical activity in the heart and the brain simultaneously (21 letters)
Microelectrophoretic — relating to a technique for separating and analyzing molecules using an electric field (19 letters)
Hematohistioblasts — a type of cell that gives rise to blood and connective tissue cells (18 letters)
Osteoarthropathy — any disease of the bones or joints, especially one accompanied by inflammation (17 letters)
Ophthalmomyiasis — an infection of the eye caused by the larvae of a fly (16 letters)
Rhinencephalic — relating to the olfactory system and the brain (13 letters)

Longest English Words with No Repeated Letters

How many long English words can you write without repeating any letters? More than you might think. Many of these words are relatively rare and aren’t commonly used in everyday speech or writing. They’re still fun to know, though!

Inconsequentially — in a manner that lacks significance or importance (16 letters)
Psychoeducational — relating to the education or treatment of people with psychological or emotional problems (16 letters)
Triskaidekaphobia — an irrational fear of the number 13 (16 letters)
Uncopyrightable — not able to be copyrighted (15 letters)
Dermatoglyphics — the study of fingerprints and related skin patterns (15 letters)
Misconjugatedly — in a manner that is not properly or correctly conjugated (15 letters)
Megakaryocyte — a large bone marrow cell that produces platelets (14 letters)
Ambidextrously — able to use both hands with equal skill (13 letters)
Unpredictably — in a manner that is not able to be foreseen or anticipated (13 letters)
Subordinately — in a manner that is less important or subordinate to something else (13 letters)
Breathtaking — causing a sudden feeling of awe or excitement (11 letters)
Flapdoodle — nonsense or foolish talk (10 letters)
Handsomely — in an attractive and impressive way (10 letters)
Strengths — the quality or state of being physically strong or capable (9 letters)
Crotchety — irritable, grouchy or difficult to please (9 letters)

Longest English Words with All 5 Vowels in Order

The longest English word that contains all 5 vowels in order is:

Uncontaminated — free from any contamination, pollution or impurity (13 letters)

However, if we include words that repeat the vowels, then there are several longer options:

Abstentious — characterized by abstention or self-restraint (11 letters)
Abstemious — marked by restraint, especially in the consumption of food or alcohol (10 letters)
Aeronautic — relating to the design and operation of aircraft (10 letters)
Autecious — being able to complete the life cycle on one host only, without a need for alternate hosts (9 letters)
Facetious — treating serious issues with inappropriate humor or flippant remarks (9 letters)
Caesious — bluish-gray or grayish-green in color (8 letters)
Anemious — having little or no wind or air movement (8 letters)

Longest Place Names in English

Place names can be long because of the history, culture or language of the region. Others are long because of the geography or location of the place. For example, lake Chargoggagoggmanchauggagoggchaubunagungamaugg in Massachusetts, USA, actually translates to “you fish on your side, I fish on my side and nobody fishes in the middle,” which describes the shape and geography of the lake.

Taumatawhakatangihangakoauauotamateaturipukakapikimaungahoronukupokaiwhenuakitanatahu — a hill in New Zealand (85 letters)
Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch — a village in Wales (58 letters)
Chargoggagoggmanchauggagoggchaubunagungamaugg — a lake in Massachusetts, USA (45 letters)
Tweebuffelsmeteenskootmorsdoodgeskietfontein — a farm in South Africa (44 letters)
Azpilicuetagaraycosaroyarenberecolarrea — a hill in Spain (39 letters)
Pekwachnamaykoskwaskwaypinwanik — a lake in Manitoba, Canada (31 letters)
Schwarzwasserbrücke — a bridge in Germany (18 letters)

Longest Nouns in English

Supercalifragilisticexpialidocious — a nonsense word popularized by the 1964 film “Mary Poppins” (34 letters)
Floccinaucinihilipilification — the act of deeming something as insignificant or unimportant (29 letters)
Spectrophotofluorometrically — in a manner that relates to the measurement of the intensity of light emitted by fluorescent substances (28 letters)
Honorificabilitudinitatibus — a medieval Latin word meaning “with honorableness” (27 letters)
Psychoneuroendocrinology — the study of the interactions between the nervous system, hormones and behavior (24 letters)
Transubstantiationalist — a person who believes in the doctrine of transubstantiation, the belief that the bread and wine of the Eucharist become the actual body and blood of Christ (22 letters)
Photomicrographically — in a manner that relates to the taking of photographs through a microscope (22 letters)
Incomprehensibilities — the state or quality of being incomprehensible or impossible to understand (21 letters)
Internationalization — the process of making something available or applicable on a global scale (20 letters)

Longest Verbs in English

Counterdemonstrate — to demonstrate in opposition to another demonstration (14 letters)
Reincorporate — to incorporate again or anew (13 letters)
Decontaminate — to remove dangerous substances from something (12 letters)
Disenfranchise — to deprive someone of a right or privilege, especially of the right to vote (12 letters)
Excommunicate — to expel from a church or other religious organization (12 letters)
Disseminate — to spread widely or to scatter (11 letters)
Encapsulate — to enclose something in a capsule (11 letters)
Extrapolate — to infer from known facts or data (11 letters)
Hypothesize — to form a hypothesis or conjecture (11 letters)
Interrogate — to question formally or search thoroughly (11 letters)

Longest Adjectives in English

Unconventionally — not following accepted standards or conventions (14 letters)
Uncontrollably — in a way that is too strong to be restrained or controlled (13 letters)
Unquestionably — in a way that cannot be doubted (13 letters)
Unforgettably — in a manner that you cannot forget it (13 letters)
Unimaginably — in a way that’s difficult to imagine (12 letters)
Unmistakably — in a way that cannot be mistaken for something else (12 letters)
Unreasonably — unfair or not based on good sense (12 letters)
Unstoppably — in a way that is unable to be stopped (11 letters)
Unthinkably — cannot be accepted as a possibility (11 letters)

Longest Suffixes in English

-fullness — shows the quality of being full or complete (8 letters)
-ization — shows the act, process or result of an action (7 letters)
-iveness — shows a quality or tendency (7 letters)
-mentum — shows a result or consequence of an action (6 letters)
-phobia — shows an extreme or irrational fear or dislike of something (6 letters)
-ectomy — shows a surgical removal of a body part or tissue (6 letters)
-titude — shows a state or quality of being (6 letters)

Longest Prefixes in English

Electro- — related to electricity (7 letters)
Pseudo- — false or not genuine (6 letters)
Immuno- — related to the immune system (6 letters)
Psycho- — related to the mind or mental processes (6 letters)
Inter- — between, among (5 letters)
Trans- — across or beyond (5 letters)
Hyper- — excessively, beyond normal (5 letters)
Super- — above, beyond (5 letters)
Ultra- — extremely, beyond normal (5 letters)
Mega- — very large, huge (5 letters)

How to Learn the Longest Words in English

Firstly: Break each word down into manageable parts

While long English words can seem complex, breaking them down into parts will make learning them easier!

Each of the words we discuss in this article, we will show you the important elements including prefixes, suffixes and roots. Let’s define the parts of a word and what they represent.

Root word: the base form of a word
Prefix: an element attached to the beginning of a root word that alters its meaning
Suffix: an element attached to the end of a root word that alters its meaning

Secondly: Use vocabulary memory tricks

Put the words and word parts onto flashcards. Flashcards are a perfect way to study and memorize long words. The language learning program FluentU allows you to make your own multimedia flashcards which are connected to a curated library of authentic videos—including news reports, inspiring talks and music videos.
Keep a running list. Track word components in a notebook. Any time you encounter a new prefix, suffix or root word, write it down in your list. This will help you keep track of the word parts you learn. You can refer to this list as you try to learn other long and complex words.

But most importantly, try to have fun with these words. Be patient and you will start pronouncing them in no time!