Today we answer the classic word lovers' question: what is the longest word in the English language?

Many of us were taught that honor falls to antidisestablishmentarianism, the 28-letter term meaning opposition to the disestablishment of the Church of England. But antidisestablishmentarianism isn't found in most dictionaries, and when it is included it is tagged rare or factitious (that is, sham or produced by special effort). We may be biased, but it seems to us that its fame rests on its status as a big word that is easily pronounced.
Now that antidisestablishmentarianism has been put in its place, we're forced to reveal what is the longest English word commonly found in unabridged dictionaries. Try Pneumonoultramicroscopicsilicovolcanoconiosis. That 45-letter tongue-twister names a lung disease that occurs especially in miners and that is caused by the inhalation of very fine silicate or quartz dust.

Well! I was taught the "pneumono" word in Grade 5 and hadn't thought about it since! Thanks, gilly! Once upon a time I could even rhyme it off! What a smarty pants I was!

....same here, lefois. I still remember it, but apparently my brain has screwed up a few syllables along the way!

You want some long words? Here are some words from my site:

Floccinaucinihilipilification (29 letters).
Hepaticocholangiocholecystenterostomy (37 letters).
Osseocarnisanguineoviscericartilaginonervomedullary (51 letters).

I have numerous other science words that I wonder if that would be of your interest.