This cannot be a new subject I am sure, but I’ll have a go anyway.

I was brought up to believe that the longest word in the English language is antidisestablishmentarian, meaning a person who is opposed to the disestablishment of the church.

Then there is the world famous Welsh railway station named:
Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch which means “Saint Mary's Church in the hollow of the white hazel near a rapid whirlpool and the church of Saint Tysilio of the red cave”. But this cannot fairly be called a word – it is more like an essay. Try this link for some pictures by the way:
http://www.onlyinternet.net/jcirillo/llan.htm

Recently I have been introduced to two other words:

pneumonoultramiscroscopicsilicovolcanoconiosis which is an inflammatory lung disease caused by the inhalation of fine silica dust. I am told this is now the longest word in the English language,

and:

floccinaucinihilipilification - the act of estimating as worthless. I am told this is the longest non-medical word in the English language, but I suspect it was invented in order to achieve that distinction. The question I have is what makes it, or would make it, officially “a word”? I am sure it can't be frequent or common usage - you can hardly (?) pronounce it.

Does any one have information regarding the derivation and provenance of flocci ….etc. or know of other challengers for the longest word? Or perhaps some suggestions for creating a new rival ourselves!