10 Longest Words in the English Language

10 Longest Words in the English Language

Last Updated: Dec 30, 2019

How many words exactly are in the English language? The second edition of the current 20-volume Oxford English Dictionary contains 171,476 words in current use. That’s a lot! Which gets the mind thinking the next question, what’s the longest word in current use today?

Many of the longest words in the dictionary refer to medicine or chemistry. You’ll find a few defined in here along with other long words that you may or may not already use. Here’s how Merriam-Webster defines the ten longest words in the English language.

1. Pneumonoultramicroscopicsilicovolcanoconiosis (45 letters)

Pneumoconiosis caused by inhalation of very fine silicate or quartz dust.

2. Hippopotomonstrosesquippedaliophobia (36 letters)

Ironically, Hippopotomonstrosesquippedaliophobia is one of the longest work in the dictionary and is the name for a fear of long words! Who would have thought, right?

3. Supercalifragilisticexpialidocious (34 letters)

Perhaps the best word of all! Made popular by the film Mary Poppins, Supercalifragilisticexpialidocious is something to say when you have nothing to say.

4. Pseudopseudohypoparathyroidism (30 letters)

A relatively mild form of pseudohypoparathyroidism that is characterized by normal levels of calcium and phosphorus in the blood.

5. Floccinaucinihilipilification (29 letters)

The longest unchallenged nontechnical word that not all directories recognize, that including Merriam-Webster. According to alternative sources, floccinaucinihilipilification is the act or habit of describing or regarding something as unimportant, of having no value or being worthless. Often times, it is used in a humorous way.

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6. Antidisestablishmentarianism (28 letters)

Opposed or hostile to the social, economic, and political principles of a ruling class (as of a nation). Opposed to the establishment.

7. Honorificabilitudinitatibus (27 letters)

The longest word in Shakespeare’s works. Honorificabilitudinitatibus is the longest word in the English language featuring alternating consonants and vowels.

8. Thyroparathyroidectomized (25 letters)

A medical term that defines the excision of both the thyroid and parathyroid glands.

9. Dichlorodifluoromethane (23 letters)

A chlorofluoromethane CF2Cl2.

10. Incomprehensibilities (21 letters)

Impossible to comprehend. In the 1990’s, incomprehensibilities set the record as the longest word “in common usage.”

LONGEST ENGLISH WORD:
Methionylthreonylthreonylglutaminylarginyl…isoleucine (189,819 letters)

If we’re talking chemistry, the longest chemical name is 189,819 letters long. It is the chemical name for titin, a giant filamentous protein essential to the structure, development, and elasticity of muscle. As to whether or not this is an actual word is disputed by many. It is not in the Merriam-Webster dictionary, so you shouldn’t ever have to worry about spelling it. 😉

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Comments

  • soo· pr· ka· luh· fra· juh· li· stuhk· ek· spee· a· luh· dow· shuhs
    Reply

    How did Supercalifragilisticexpialidocious become a real word in the dictionary from a show? And yes I am too lazy to search it my self. Also, the girl with the longest name try and beat that.

  • BillGates
    Reply

    good job

  • Gail Warren
    Reply

    paradimethylaminobenzaldehyde

    • Alek Sander

      Oooooh good one!

  • shelley
    Reply

    wow, looooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong English word!

  • Joshua Griffiths
    Reply

    wow good job for pronouncing that long word your amazing!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1

  • Sam
    Reply

    what about supercalifragilisticexpialidocious?

  • Backnineblues
    Reply

    How about “uncharacteristically”

  • Harry Green
    Reply

    Common long word:

    Uncharacteristically – 20 digits

    • David

      Amorphophalouscompanulatuse

      • Alek Sander

        This is great. The comments are making this the best blog post ever!!!

    • Kevin

      credit for you people commenting and a person who made this

    • Ella

      digits are for numbers, letters are for words

  • XxSmartiexX
    Reply

    floccinaucinihilipilification-the estimation of something as worthless – 29 letters.

    • XxSmartiexX

      sry didnt see it up there

  • IM NOT A ROBOT (OR AM I)
    Reply

    Euouae is the longest word with only vowels.

    • XxSmartiexX

      what does it mean?

    • This Is You

      yeah what it mean

    • Don’t be Lazzzy peeps

      look it up, y’all have internet

  • Me (AGAIN)
    Reply

    Methionylthreonylthreonylglutaminylarginyl…isoleucine, longest known protien. It has 189,819 letters.

  • Jeffery_Who_Is_Actually_Female
    Reply

    Hey, you left out one of my very favorite words! Hippocrampusenjutgenduswavelousis!
    PWEASE PUT IT IN
    PWEASE PWEASE PWEASE PWEASE PWEASE

  • Idk
    Reply

    Hexakosioihexekontahexaphobia

    29 characters is the fear of the number 666

    • Anonymous

      =Plz add da protein that has 189819 letters. PLS

      • Alek Sander

        Done!

  • Bobby Bentrus
    Reply

    chlorofluoromethane almost made it! That was funny

  • Paul Nowak
    Reply

    This post was just updated to include videos with pronunciation. Good luck trying to verbalize these words!

  • Unknown
    Reply

    What about PSEUDOPSEUDOHYPOPARATHYROIDISM??

    • Unknown

      Its 30 letters so it would fall as 4th or 5th place in this.

    • Paul Nowak

      Good catch. Updated!

    • Me (AGAIN)

      Methionylthreonylthreonylglutaminylarginyl…isoleucine, longest known protien. It has 189,819 letters. TOO LONG

  • Nancy
    Reply

    I am reading this because of my school compdition 😒

  • Jaxson
    Reply

    Wheres Hippopotomonstrosesquipwdaliophobia. It’s 35 letters.

  • georgie
    Reply

    dichlorodiphenyltrichloroethane is 31 letters. It’s a chlorine compound

    • Alek Sander

      That’s a good one. Thanks! We’ll update the post.

  • basher
    Reply

    what About Congratulations ?

  • Harshee Patel
    Reply

    These are words I’ve never heard

    • xXYeahItsMeCreeperXx

      what the @:!? they made that words
      but,How about Marshmallow?

      • Alek Sander

        Marshmallows are delicious!

  • bob
    Reply

    that is a good word

  • ???
    Reply

    This is a good website but you could also add Antidisestablishmentarianism which has twenty-eight letters and is originally described opposition to the disestablishment of the Church of England, but now it may refer to any opposition to withdrawing government support of a particular church or religion.

    • Paul Nowak

      We have updated our post to reflect your added wisdom! Thank you!

  • KAREN BLUMENTHAL
    Reply

    YOU LEFT OUT HIPPOPOTOMONSTROSESQUIPPEDALIOPHOBIA

    FEAR OF LONG WORDS….

    • Oh my goodness

      That’s literally what I came here for… also it’s hippopotomonstrosesquippedaliophobia… that’s too long to write here (0^0)

    • Hannah

      Is that actually a thing

    • bro

      Yes don’t forget hippopotomostreusquippdeloilaphobia

      • Alek Sander

        Thanks! We’ll update the post.

    • Paul Nowak

      Updated. #2 on the list!