Definition: ”Properly, opposition to the disestablishment of the Church of England” (Oxford English Dictionary)

“My favorite word is PARTY. My second favorite word is HARD. And my third favorite word is ANTIDISESTABLISHMENTARIANISM”

—Twitter User, 22 June 2013

If you spend any significant amount of time looking at lists that people make of their favorite obscure words in English (and the Internet is awash with such things), you will very quickly notice one salient characteristic that most of the entries share: they are made up of exceedingly long words. You are unlikely to find many lists composed of the likes of bur, pip, and ut. It is uncertain why we have such a fascination with lengthy words, although a desire to appear learned probably has something to do with it. Antidisestablishmentarianism is a splendid example of a word that people enjoy for some reason other than its ostensibly intended use; they like it because it is a very long word. Merriam-Webster does not define the word, on the grounds that very few people (if any) ever use it, except as an example of a long word. The Oxford English Dictionary does define it, but also notes that it is “popularly cited as an example of a long word."

The word has been in use as an example of a mouthful of syllables for slightly over a hundred years now, and it seems likely that it has had a far more successful career as a curio than it ever would have had as a description of the opposition to the disestablishment of a church.