What is the longest English word According to Oxford?
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:
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 Latin word honorificabilitudinitas (honourableness) was listed by some old dictionaries in the English form honorificabilitudinity (22 letters), but it has never really been in use. The longest word currently listed in Oxford dictionaries is rather of this kind: it is the supposed lung-disease