The 10 Longest Words in English and How They’ll Help You Master Vocab

The longest word in the English language is Pneumonoultramicroscopicsilicovolcanoconiosis.

Try saying that five times fast.

If you want to add long English words like this to your vocabulary and be able to really use them, you need to break them down into their basic parts.

Today we’ll go over 10 of the longest words in English, teach you how to break them down and show you how they can build your vocabulary.


The 10 Longest Words in English

longest word 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.


Definition (noun): lung disease caused 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)
  • Common suffix: -osis (often indicates a disease)


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.

Whenever you are unsure of a word (or its word parts), do not be afraid to spend time researching the word’s origin. Online Etymology Dictionary is a helpful resource to do this.

Essential word parts:

  • nihili- (nothing)


Definition (noun): The state of being 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:

  • Common prefix: in- (not)
  • Common root word: prehend (from the Latin for “grasp”)
  • Common suffix: –ity (suffix used to form a noun out of an adjective)


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 parts:

  • Common prefix: sur- (under, below)


Definition (adverb): In a way that is not typical/unusual for a person or thing to behave

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:

  • Common prefix: un- (not)
  • Common suffix: -ly (used to form an adjective)


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)


Definition (adjective): involving the patterns under the skin that determine what our fingerprints look like

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.

Though this word is rare, it is made up of some common word parts. Try to memorize these parts and look for them in other English words.

Essential word parts:

  • Common prefix: sub- (under, below — similar to “sur-“)
  • derma- (skin)
  • Common suffix: -ic (used to form an adjective)


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:

  • Common suffix: -ious (used to form an adjective)


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:

  • Common prefix: un- (not)
  • Common suffix: -able (ability)


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:

  • Common suffix: -phobia (fear)

How to Learn the Longest Words in English

longest word in english

Break each word down into manageable parts

Long English words can seem complex and overwhelming. But remember, breaking down the word into its parts will make learning these long words more manageable.

For each of the words we discuss in this article, we will show you the important elements including prefixes, suffixes and roots.

So, before we go any further, we should define these terms to make sure we are all on the same page:

  • 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

We will show you many examples for the words in this article.

Use vocabulary memory tricks

  • Put the words and word parts onto flashcards. It may seem old-school, but flashcards are a perfect way to study and memorize long words and their parts. Consider downloading an English flashcard app so you can bring your flashcards with you anywhere you go.

Flip through the cards while you are standing in line at the grocery store or waiting for the bus.

  • Keep a running list. Track word components in a physical or online 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.

If you are having trouble fully understanding the meaning of a long English word, the Oxford Learner’s Dictionary is a great resource.

  • Do not get overwhelmed. Yes, the longest English words can seem overwhelming. But try to be patient with yourself. Learning long words takes time and you will not master them overnight. Be calm and tackle these words slowly.
  • Have fun. Most importantly, try to have fun with these words. Practice saying these long words and laugh when you mess up the pronunciations (even fluent English speakers struggle with these complex words).

Why Learn the Longest Words in English?

longest word in english

To communicate more effectively

Learning long words will help expand your English vocabulary. Although some of these words are very rare, others are actually fairly useful (as you will see in our list below). Knowing long, specific words will allow you to express more complex and precise ideas.

Be able to understand more words 

As you break down long English words, you will start to recognize the common elements found in many different English words. This will help you understand more English words without doing any extra vocabulary studies.

Learn more about word origins

Many English words actually originated from Greek, Latin, Arabic, French and other languages. And many of the longest words in English developed from these languages.

Understanding this can make English seem less strange or foreign. It can also help you learn more about the history behind language development.

Gain practice with written and spoken English

Any time you study the English language, you are improving your fluency. As you practice breaking down long words, you will gain additional experience with the written and spoken English language.


Just remember to be patient and break down long words. Soon you’ll be able to understand the longest words in English — and lots of other words, too.


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