Do you remember – when you were a child – learning (then gleefully reciting) what youthought was the longest word in the English language? Was it ANTI­DIS­ESTABLISH­MENT­ARIAN­ISM? Or the similarly long SUPER­CALI­FRAGI­LISTIC­EXPI­ALI­DOCIOUS?

There are longer ones...

However, there is no easy answer that we can give when our visitors ask us for the longest word in the English language. Most very long words only occur in one or two dictionaries, and often they are debatably not words at all. For example, ANTI­DIS­ESTABLISH­MENT­ARIAN­ISM has possibly never really been used to mean "the belief which opposes removing the tie between church and state." Certainly 99 in 100 times it is used as an example of a long word. And who says you can't put NON– (for example) on the beginning to make it even longer?

This problem is even more evident in chemical names. Most chemicals are named using a systematic naming system which methodically describes the molecule's structure. Some molecules, such as proteins, are huge, so it is possible to come up with genuine words containing millions of letters. But of course no chemist uses these really long names in practice.

Here we look at some of the longest words in English dictionaries, and discuss whether they should be considered to be real words. Interesting long chemical termsand place names are listed separately afterwards. The red numbers indicate the length (number of letters) of the word that follows.

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Longest Words

(45) PNEUMONO­ULTRA­MICRO­SCOPIC­SILICO­VOLCANO­CONIOSIS (also spelledPNEUMONO­ULTRA­MICRO­SCOPIC­SILICO­VOLCANO­KONIOSIS) = a lung disease caused by breathing in particles of siliceous volcanic dust.

This is the longest word in any English dictionary. However, it was coined by Everett Smith, the President of The National Puzzlers' League, in 1935 purely for the purpose of inventing a new "longest word". The Oxford English Dictionary described the word as factitious. Nevertheless it also appears in the Webster's, Random House, andChambers dictionaries.

(37) HEPATICO­CHOLANGIO­CHOLECYST­ENTERO­STOMIES = a surgical creation of a connection between the gall bladder and a hepatic duct and between the intestine and the gall bladder.

This is the longest word in Gould's Medical Dictionary.

(34) SUPER­CALI­FRAGI­LISTIC­EXPI­ALI­DOCIOUS = song title from the Walt Disney movie Mary Poppins.

It is in the Oxford English Dictionary.

"But then one day I learned a word

That saved me achin' nose,

The biggest word you ever 'eard,

And this is 'ow it goes:

Supercalifragilisticexpialidocious!"

(30) HIPPOPOTO­MONSTRO­SESQUIPED­AL­IAN = pertaining to a very long word.

From Mrs. Byrne's Dictionary of Unusual, Obscure and Preposterous Words.

(29) FLOCCI­NAUCINI­HILIPIL­IFICATION = an estimation of something as worthless.

This is the longest word in the first edition of the Oxford English Dictionary. Interestingly the most common letter in English, E, does not appear in this word at all, whilst I occurs a total of nine times. The word dates back to 1741. The 1992 Guinness Book of World Records calls flocci­nauci­nihili­pilification the longest real word in theOxford English Dictionary, and refers to pneumono­ultra­micro­scopic­silico­volcano­koniosis as the longest made-up one.

(28) ANTI­DIS­ESTABLISH­MENT­ARIAN­ISM = the belief which opposes removing the tie between church and state.

Probably the most popular of the "longest words" in recent decades.

(27) HONORI­FICABILI­TUDINI­TATIBUS = honorableness.

The word first appeared in English in 1599, and in 1721 was listed by Bailey's Dictionary as the longest word in English. It was used by Shakespeare in Love's Labor's Lost (Costard; Act V, Scene I):

"O, they have lived long on the alms-basket of words.

I marvel thy master hath not eaten thee for a word;

for thou art not so long by the head as

honorificabilitudinitatibus: thou art easier

swallowed than a flap-dragon."

Shakespeare does not use any other words over 17 letters in length.

(27) ELECTRO­ENCEPHALO­GRAPHICALLY

The longest unhyphenated word in Merriam-Webster's Collegiate Dictionary (10th Ed.), joint with ethylene­diamine­tetraacetate (see below).

(27) ANTI­TRANSUB­STAN­TIA­TION­ALIST = one who doubts that consecrated bread and wine actually change into the body and blood of Christ.

(21) DIS­PRO­PORTION­ABLE­NESS and (21) IN­COM­PREHEN­SIB­ILITIES

These are described by the 1992 Guinness Book of World Records as the longest words in common usage.

Some say SMILES is the longest word because there is a MILE between the first and last letters!

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Chemical Terms

Two chemical terms (3,641 and 1,913 letters long) have appeared in the Guinness Book of World Records. They were withdrawn because they have never been used by chemists, and there is no theoretical limit to the length of possible legitimate chemical terms. A DNA molecule could have a name of over 1,000,000,000 letters if it was written out in full.

(1,185) ACETYL­SERYL­TYROSYL­SERYL­ISO­LEUCYL­THREONYL­SERYL­PROLYL­SERYL­GLUTAMINYL­PHENYL­ALANYL­VALYL­PHENYL­ALANYL­LEUCYL­SERYL­SERYL­VALYL­TRYPTOPHYL­ALANYL­ASPARTYL­PROLYL­ISOLEUCYL­GLUTAMYL­LEUCYL­LEUCYL­ASPARAGINYL­VALYL­CYSTEINYL­THREONYL­SERYL­SERYL­LEUCYL­GLYCYL­ASPARAGINYL­GLUTAMINYL­PHENYL­ALANYL­GLUTAMINYL­THREONYL­GLUTAMINYL­GLUTAMINYL­ALANYL­ARGINYL­THREONYL­THREONYL­GLUTAMINYL­VALYL­GLUTAMINYL­GLUTAMINYL­PHENYL­ALANYL­SERYL­GLUTAMINYL­VALYL­TRYPTOPHYL­LYSYL­PROLYL­PHENYL­ALANYL­PROLYL­GLUTAMINYL­SERYL­THREONYL­VALYL­ARGINYL­PHENYL­ALANYL­PROLYL­GLYCYL­ASPARTYL­VALYL­TYROSYL­LYSYL­VALYL­TYROSYL­ARGINYL­TYROSYL­ASPARAGINYL­ALANYL­VALYL­LEUCYL­ASPARTYL­PROLYL­LEUCYL­ISOLEUCYL­THREONYL­ALANYL­LEUCYL­LEUCYL­GLYCYL­THREONYL­PHENYL­ALANYL­ASPARTYL­THREONYL­ARGINYL­ASPARAGINYL­ARGINYL­ISOLEUCYL­ISOLEUCYL­GLUTAMYL­VALYL­GLUTAMYL­ASPARAGINYL­GLUTAMINYL­GLUTAMINYL­SERYL­PROLYL­THREONYL­THREONYL­ALANYL­GLUTAMYL­THREONYL­LEUCYL­ASPARTYL­ALANYL­THREONYL­ARGINYL­ARGINYL­VALYL­ASPARTYL­ASPARTYL­ALANYL­THREONYL­VALYL­ALANYL­ISOLEUCYL­ARGINYL­SERYL­ALANYL­ASPARAGINYL­ISOLEUCYL­ASPARAGINYL­LEUCYL­VALYL­ASPARAGINYL­GLUTAMYL­LEUCYL­VALYL­ARGINYL­GLYCYL­THREONYL­GLYCYL­LEUCYL­TYROSYL­ASPARAGINYL­GLUTAMINYL­ASPARAGINYL­THREONYL­PHENYL­ALANYL­GLUTAMYL­SERYL­METHIONYL­SERYL­GLYCYL­LEUCYL­VALYL­TRYPTOPHYL­THREONYL­SERYL­ALANYL­PROLYL­ALANYL­SERINE = Tobacco Mosaic Virus, Dahlemense Strain.

This word has appeared in the American Chemical Society's Chemical Abstracts and is thus considered by some to be the longest real word.

(39) TETRA­METHYL­DIAMINO­BENZHYDRYL­PHOSPHINOUS = a type of acid.

This is the longest chemical term in the Oxford English Dictionary (2nd Ed.). It does not have its own entry but appears under a citation for another word.

(37) FORMALDEHYDE­TETRA­METHYL­AMIDO­FLUORIMUM

Chemical term in the Oxford English Dictionary (2nd Ed.).

(37) DIMETHYL­AMIDO­PHENYL­DIMETHYL­PYRAZOLONE

Chemical term in the Oxford English Dictionary (2nd Ed.).

(31) DICHLORO­DIPHENYL­TRICHLORO­ETHANE = a pesticide used to kill lice; abbrv. DDT.

It is the longest word in the Macquarie Dictionary and is also in the Oxford English Dictionary (2nd Ed.).

(29) TRINITRO­PHENYL­METHYL­NITRAMINE = a type of explosive.

This is the longest chemical term in Webster's Dictionary (3rd Ed.).

(27) ETHYLENE­DIAMINE­TETRA­ACETATE

The longest unhyphenated word in Merriam-Webster's Collegiate Dictionary (10th Ed.), joint with electroencephalographically (see above).

(26) ETHYLENE­DIAMINE­TETRA­ACETIC = a type of acid; abbrv. EDTA.

This word appears in Merriam-Webster's Collegiate Dictionary (10th Ed.).

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Place Names

There are many long place names around the world. Here are a few of the largest.

(85) TAUMATA­WHAKA­TANGI­HANGA­KOAUAU­O­TAMATEA­TURIPUKAKA­PIKI­MAUNGA­HORO­NUKU­POKAI­WHENUA­KITANA­TAHU

A hill in New Zealand. This Maori name was in general use, but is now generally abbreviated to Taumata. The name means: the summit of the hill, where Tamatea, who is known as the land eater, slid down, climbed up and swallowed mountains, played on his nose flute to his loved one.

(66) GORSA­FAWDDACH­AIDRAIGODAN­HEDDO­GLEDDOLON­PENRHYN­AREUR­DRAETH­CEREDIGION

A town in Wales. The name means: the Mawddach station and its dragon teeth at the Northern Penrhyn Road on the golden beach of Cardigan bay.

(58) LLAN­FAIR­PWLL­GWYN­GYLL­GOGERY­CHWYRN­DROBWLL­LLANTY­SILIO­GOGO­GOCH

A town in North Wales. The name roughly translates as: St. Mary's Church in the hollow of the white hazel near to the rapid whirlpool of Llantysilio of the red cave. It is listed in the Guinness Book of World Records.

(41) CHAR­GOGAGOG­MAN­CHAR­GOGAGOG­CHAR­BUNA­GUNGAMOG

Another name for Lake Webster in Massachusetts. Probably the longest name in the United States. Alternative spellings are:

(44) CHAR­GOGGAGOGG­MAN­CHAUG­GAGOGG­CHAU­BUNA­GUNGAMOGG,

(45) CHAR­GOGGAGOGG­MAN­CHAUG­GAGOGG­CHAU­BUNA­GUNGAMAUGG,

(44) CHAR­GOGGAGOGG­MAN­CHAUG­GAGOGG­CHA­BUNA­GUNGAMAUGG.

(23) NUNATH­LOOGAGA­MIUT­BINGOI

The Eskimo name for some dunes in Alaska, according to The Book of Names by J. N. Hook.

Vowel Word Records

Vowels

Here is a collection of words notable for their vowels. Some have many, some have few; some contain them all, some contain none.

Note that we are talking about the five true vowels in the English alphabet: A, E, I, O, and U. Sometimes the consonant Y may be pronounced as a vowel, as may other letters in rare words, such as W in some words of Welsh origin.

Many Vowels

Words (found in major English dictionaries) consisting entirely of vowels include AA(a type of lava), AE, AI, AIEEE, IAO, OII, EAU, EUOUAE, OE, OO, I, O, A, IO, and UOIAUAI, the last of these being the longest vowel-only word (seven letters).

OUENOUAOU (a stream in the Philippines) has nine letters but only one consonant. It is the longest known place name with only a single consonant.

The English dictionary word with the most consecutive vowels (six) is EUOUAE. Words with five consecutive vowels include QUEUEING, AIEEE, COOEEING, MIAOUED,ZAOUIA, JUSSIEUEAN, ZOOEAE, ZOAEAE. The Hawaiian word HOOIAIOIA (meaning certified) has eight consecutive vowels and is listed in the 1976 Guinness Book of World Records. Allowing proper nouns, URU-EU-UAU-UAU (a language of Brazil) has nine vowels in a row, ignoring hyphens.

HONORIFICABILITUDINITATIBUS is the longest word consisting entirely of alternating vowels and consonants. Other such words are ALUMINOSILICATES,EPICORACOHUMERALER, HEXOSAMINIDASES, ICULANIBOKOLAS,PARAROSANILINES, PARASITOLOGICAL, VERISIMILITUDES. GORAN IVANESEVIC (a top tennis player) is the longest known celebrity name that alternates consonants and vowels. UNITED ARAB EMIRATES is the longest name of a country consisting of alternating vowels and consonants.

Few Vowels

The longest common word without any of the five vowels is RHYTHMS, but there are longer rare words: SYMPHYSY, NYMPHLY, GYPSYRY, GYPSYFY, andTWYNDYLLYNGS. WPPWRMWSTE and GLYCYRRHIZIN are long words with very few vowels.

ASTHMA begins and ends with a vowel and has no other vowels in between. Some less common long words with this property are ISTHMI (alternate plural of isthmus),APHTHA, and ELTCHI.

The longest word in dictionaries having only one vowel is STRENGTHS. The longest word with only one vowel (if repeats are allowed) is CHRONONHOTONTHOLOGOS(twenty letters). STRENGTHLESSNESSES contains only Es and is just two letters shorter.

The Five Vowels

The shortest word containing all five vowels exactly once is the six-letter EUNOIA, meaning alertness of mind an will (and also the title of a book by Canadian poet Christian Bok). However, it is not included in any major English dictionary. There are several seven-letter words containing all the vowels, including SEQUOIA, EULOGIA,MIAOUED, ADOULIE, EUCOSIA, EUNOMIA, EUTOPIA, MOINEAU, and DOULEIA. The relatively common French word OISEAU (meaning bird) contains all five vowels, once each.

The shortest word with the five vowels occurring in alphabetical order is AERIOUS(airy), which has seven letters. The longest such word is PHRAGELLIORHYNCHUS (a protozoan) with 18 letters. There are two seven-letter words in Portuguese that contain the five vowels in alphabetical order: ACEITOU and ALEIJOU.

SUOIDEA (the taxonomic group to which pigs belong) is the shortest word with the five vowels in reverse alphabetical order. The longest such word isPUNCTOSCHMIDTELLA (a crustacean).

ULTRAREVOLUTIONARIES has each vowel exactly twice. The shortest such word isCUBOIDEONAVICULARE, and the longest, USSOLZEWIECHINOGAMMARUS (a small crustacean).