Which is the longest word in an English dictionary?
From AskOxford.com (as in the Oxford English Dictionary): We do have genuine (if rather obviously deliberate) examples in our files of antidisestablishmentarianism (28 letters) and floccinaucinihilipilification (29 letters), which are listed in some of our larger dictionaries. Other words (mainly technical ones) recorded in the complete Oxford English Dictionary include: otorhinolaryngological (22 letters), immunoelectrophoretically (25 letters), psychophysicotherapeutics (25 letters), thyroparathyroidectomized (25 letters), pneumoencephalographically (26 letters), radioimmunoelectrophoresis (26 letters), psychoneuroendocrinological (27 letters) hepaticocholangiogastrostomy (28 letters), spectrophotofluorometrically (28 letters), pseudopseudohypoparathyroidism (30 letters). Most of the words which are given as ‘the longest word’ are merely inventions, and when they occur it is almost always as examples of long words, rather than as genuine examples of use. For example, the medieval Lat
The longest official word ever (1,913 letters) is the term for the formula C1289H2051N343O375S8. methionylglutaminylarginyltyrosylglutamylse- rylleucylphenylalanylalanylglutaminylleucyl- lysylglutamylarginyllysylglutamylglycylalan- ylphenylalanylvalylprolylphenylalanylvalylt- hreonylleucylglycylaspartylprolylglycylisol- eucylglutamylglutaminylserylleucyllysylisol- eucylaspartylthreonylleucylisoleucylglutamy- lalanylglycylalanylaspartylalanylleucylglut- amylleucylglycylisoleucylprolylphenylalanyl- serylaspartylprolylleucylalanylaspartylglyc- ylprolylthreonylisoleucylglutaminylasparagi- nylalanylthreonylleucylarginylalanylphenyla- lanylalanylalanylglycylvalylthreonylprolyla- lanylglutaminylcysteinylphenylalanylglutamy- lmethionylleucylalanylleucylisoleucylarginy- lglutaminyllysylhistidylprolylthreonylisole- ucylprolylisoleucylglycylleucylleucylmethio- nyltyrosylalanylasparaginylleucylvalylpheny- lalanylasparaginyllysylglycylisoleucylaspar- tylglutamylphenylalanyltyrosylalanylglutami- nyl
‘Floccinaucinihilipilification’ is a very complicated 29-letter word for the deeming of something as worthless; but it is the longest word in the English language outside of purely technical jargon. One example of a long-winded word that arises from technical jargon is ‘aminoheptafluorocyclotetraphosphonitrile’, the 40-letter formal name for a chemical compound (unusual for long-winded chemical names as others tend to include numbers or special characters. ‘Pneumonoultramicroscopicsilicovolcanoconiosis’, or the 45-letter name for an alleged lung disease caused by the inhalation of very fine silica dust, is another extremely long word (some would say that this word doesn’t count as it’s main purpose isn’t to name an actual disease but to create an extra-long word).
PNEUMONOULTRAMICROSCOPICSILICOVOLCANOCONIOSIS (also spelled PNEUMONOULTRAMICROSCOPICSILICOVOLCANOKONIOSIS) = 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, and Chambers dictionaries.
