The longest word in the English Dictionary

When I was growing up, antidisestablishmentarianism was quoted by masters at school as the longest word in English. But at a mere 28 characters it is something of a pygmy in comparison with, pneumonoultramicroscopicsilicovolcanoconiosis, an invented, pseudo-scientific term for a type of lung disease, with its 45 letters.

So, what really is the longest word in English, and which is the longest word in “the dictionary”? Those questions can only be answered satisfactorily by first posing and then answering some prior questions that they raise.

What is a word?

What do you class as a word for these purposes?

Can you include names, such as the legendary Welsh place name Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch?
Do you count invented words such as supercalifragilisticexpialidocious, made famous by the film Mary Poppins?

Or do you only include words that have been created by actual usage? If so, antidisestablishmentarianism might be a better candidate than some.
Do you include scientific names, such as that ne plus ultra of sesquipedalianism, the scientific name for the protein titin, which starts Methionyl… and goes on for another 189,910 letters (yes, that’s right, you didn’t misread it: one hundred and eighty-nine thousand, nine hundred and ten).

What does “in the dictionary” mean?

The first question is: which dictionary? Not all dictionaries are equal. The Oxford English Dictionary and the Oxford Dictionary Online both include the supercali… word; Collins, Merriam-Webster online, and Macquarie do not. The two Oxford dictionaries, and Macquarie include floccinaucinihilpilification; Collins and M-W do not.

Technical or non-technical?

Broadly speaking, the dictionaries mentioned above are, apart from the OED, general dictionaries that anyone might readily consult. But in scientific areas, only specialists in the discipline concerned will consult such volumes as, for example, the Royal Society of Chemistry’s Nomenclature of Inorganic Chemistry (known as the “Red Book”), which states the rules for naming inorganic compounds.

And do you include words that appear in dictionaries of foreign languages, and have been translated or transliterated into English? If so, you might give some thought to the 183 letters of the Classical Greek

“Lopadotemachoselachogaleokranioleipsanodrimhypotrimmatosil

phioparabomelitokatakechymenokichlepikossyphophattoperistera

lektryonoptekephalliokigklopeleiolagoiosiraiobaphetraganopterygon“.

This is a transliteration of a comical word coined by the Greek playwright Aristophanes to describe a fictional dish that is defined by Liddell & Scott as “compounded of all kinds of dainties, fish, flesh, fowl, and sauces”. Since the dish never existed, we need not be put off by its rebarbative mixture of fish, meat, seafood, fowl, and birds.

What is interesting is that the fascination with long words is clearly not just a modern curiosity, the result of printing and universal literacy. The Aristophanic word suggests that it is clearly ancient. It makes you wonder just how often Greeks in the Classical Age asked themselves: “I wonder what the longest word is…”

Filed under: Dictionaries & Lexicography, Grammar, OED, Oxford Online Dictionary Tagged: Longest word