15 of the longest words in French that'll truly twist your tongue

We all remember the infamous Icelandic eruption of 2010, and the struggle of TV anchors around the world to pronounce Eyjafjallajökull. 

Yep, as you can see in this video, French speakers don’t do well with looooooong words.

By the way, it’s kind of ironic that the longest word in the English dictionary is related to volcanos (pneumonoultramicroscopicsilicovolcanoconiosis)!

However, despite the francophone aversion for never-ending terms, there are long words in French. Ok, maybe not as long as in English, but still long enough to have some fun when trying to pronounce them.

Let’s be honest: knowing the longest word in French is not super helpful, but can you imagine the face of your francophone friends when you place it in a conversation? It’s also a great exercise to work on your French pronunciation and vocab.

So, if you’re up to the challenge, keep reading to discover the longest French word. Doesn’t it sound supercalifragilisticexpidélilicieux?

What is the longest word in the French language dictionary?

If you ask any native French speaker: “What is the longest word in the French dictionary”, they’ll most likely answer… drum roll… “anticonstitutionnellement”. Bless you!

Anticonstitutionnellement meaning

This 25-lettered word, which might give you trichotillomanie (the urge to pull out one’s hair), means "anticonstitutionally", that is, not conforming to the constitution.

How to pronounce the longest word in French

With 25 letters, the much debated longest French word in the world is not THAT hard to pronounce. Come on, give it a try! No, not like this… like that!

  • IPA: \ɑ̃.ti.kɔ̃s.ti.ty.sjɔ.nɛl.mɑ̃\

15 of the longest words in French

Get ready to impress your francophone amis with these formidable French words! Conquer these, and you can conquer anything, really.

1. hippopotomonstrosesquipédaliophobie

IPA: ipɔpɔtɔmõstɾozɛskipedaljɔpɔbjə

Meaning: The fear of long words.

2. hexakosioihexekontahexaphobie

IPA: ɛgzakozjwaɛgzəkõtaɛgzapɔbjə

Meaning: The fear of number 666.

3. diisobutylphénoxyéthoxyéthyldiméthylbenzylammonium

IPA: djizɔbytilpenɔgzjetɔgzjetildimetilbɑ̃zilamɔnjœ̃

Meaning: An ammonium with bactericidal.

4. Apopathodiaphulatophobie

IPA: apɔpatɔdjapylatɔpɔbjə

Meaning: The fear of being constipated.

5. orthochlorobenzalmalonitrile

IPA: ɔɾtɔʃlɔɾɔbɑ̃zalmalɔnitɾilə

Meaning: A suffocating toxic gas.

6. contraventionnalisation

IPA: kõtɾavɑ̃tjɔnalizasjõ

Meaning: Means that an offence (misdemeanour or felony) is reclassified as a contravention.

7. intergouvernementalisation

IPA: ɛ̃tɛɾguvɛɾnəmɑ̃talizasjõ

Meaning: Implementation by several governments of a common policy or action.

8. dichlorodiphenyltrichloroethane

IPA: diʃlɔɾɔdipɛniltɾiʃlɔɾœtanə

Meaning: DDT (insecticide used in agriculture until the 70s).

9. cyclopentanoperhydrophénanthrène

IPA: siklɔpɑ̃tanɔpɛɾidɾɔpenɑ̃tɾɛnə

Meaning: A four-ringed core that is part of the composition of biochemical elements such as cholesterol.

10. heptathalassoédimbourgeoises

IPA: ɛptatalasoedɛ̃buɾʒɛwazə

Meaning: Inhabitants of Edimbourg-des-sept-mers.

11. psychopharmacothérapeutique

IPA: psiʃɔpaɾmakɔteɾapœtikə

Meaning: Treatment of psychological disorders through the administration of medication.

12. déconstitutionnalisassions

IPA: dekõstitytjɔnalizasjõ

Meaning: Verb “déconstitutionnaliser” in the imperfect subjunctive.

13. intradermotuberculination

IPA: ɛ̃tɾadɛɾmɔtybɛɾkylinasjõ

Meaning: Live animal screening tool for bovine tuberculosis

14. interdépartementalisation

IPA: ɛ̃tɛɾdepaɾtəmɑ̃talizasjõ

Meaning: Joint implementation by several French departments.

15. hyperprésidentialisation

IPA: ipɛɾpɾezidɑ̃tjalizasjõ

Meaning: Designates the omnipresence of the president, intervening in person on all issues and constantly occupyi

What is the longest word in French? Fun facts

Happy diverse friends saying cheers to the longest words in French with Aperol Spritz rose wine.

If you’ve been following our French blog for a while, you probably know there’s rarely a definite answer to any French language question. And the answer to What is the longest word in the French dictionaryis no exception!

While “anticonstitutionnellement” seems to be the winner according to many, as you can read in this article, this seems to be an animated debate around the Christmas table!

What is the longest one-syllable word in French?

“Pschents” is the longest monosyllabic word in French. If, like me, you’ve just learned a new word, you’ll be happy to know it refers to the double crown worn by ancient Egyptian kings — in the plural form to add a letter!

Some will argue that “Schtroumpfs” has more letters. What, aren’t the smurfs part of the dictionary? And just because you made the effort to read this article and pronounce these brontosorusneckstic – a word I made up — words, here is a little reward: Les Schtroumpfs, le générique.

What is the longest French word without vowels?

Oddly enough, the only words without vowels in French are “onomatopées”, the longest counting only 4 letters:

  • Brrr: To express that you’re cold
  • Grrr: Typically a dog growling, but can also be used by humans as a sign of discontentment. Very French!
  • Pfft: To express indifference, disdain. Again, so French!
  • Psst: To call someone’s attention.

And for your next Scrabble game, take note: The longest word without consonants is “Ouie” (hearing).

By the way, Scrabble is a great way to spice up your French vocab!

What is the longest number in French?

Take a deep breath… Ready… steady… go: “quatre-cent-quatre-vingt-quatorze-mille-quatre-cent-quatre-vingt-quatorzièmes”.

I don’t know about you, but I’m having a hippopotomonstrosesquippedaliophobie crisisright now.

With 73 letters, it’s the ordinal number 494 494e in its plural form.

What is the longest French palindrome word?

I know, I know, you’ve already learned a lot of trivia answers, but here is one more if you didn’t know.

A palindrome is a word, sequence or phrase that reads the same forwards as backwards, e.g. “madam”, “noon”, “level” or “civic” in English.

In French, the longest palindrome word is “Ressasser”, which means “Dwell on”.

Example: Il ressasse tout le temps les mêmes histoires. (He’s always dwelling on the same stories).

Other long words in French that are challenging to pronounce

Ok, French pronunciation is not always “un jeu d’enfants”. Check out this video of Americans trying to pronounce French words: you’re not alone! But as Mark Twain wisely said, “They did not know it was impossible, so they did it.”

Napoléon also said that “Impossible is not French”. So get into the French combative spirit and tackle the words below! — but maybe don’t follow Napoléon’s example…

French IPA English meaning
Mille-feuille milə-fœjə Mille-feuille
(a mouth-watering French pastry made of puff pastry and cream)
Bouillloire bwijlwaɾə Kettle
Grenouille gɾənwijə Frog
Serrurerier sɛryɾəɾje Locksmith
Écureuil ekyɾœj Squirrel
Guillotine gijɔtinə Guillotine
Caoutchouc kautʃuk Rubber
Chirurgien ʃiɾyɾʒjɛ̃ Surgeon
Quincaillerie kɛ̃kajəɾjə Hardware store
Hiérarchie jeɾaɾʃjə Hierarchy
Architecte aɾʃitɛktə Architect
Dévérouiller deveɾwije To unlock
Archéologie aɾʃeɔlɔʒjə Archaeology
Meurtrier mœɾtɾje Murderer

My American fiancé also has some trouble with “eau”, œufs and “deux”. And you’ll find more wild French words to practice — and show off — your pronunciation skills here!

Now that you know some of the most complicated and longest French words, you’re ready to conquer the world — not like Napoléon, though!

And if you’re not quite there yet, check out our French learning blog, or our French online lessons.

And remember: the best way to cure your hippopotomonstrosesquipédaliophobie is to face it head's on and learn more long words!

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