In Longest words^x

It might be 'supercalifragilisticexpialidocious' (which appears in the Oxford English Dictionary), unless you want to count names of diseases (such as 'pneumonoultramicroscopicsilicovolcanoconiosis', defined by the OED as "a factitious word alleged to mean 'a lung disease caused by the inhalation...

and i always heard the longest word was antidisestablishmentarianism (the scientific words are hardly english!)

We had this here: Longest word in the english language

Dear sir/Madam what is the longest word in english language? truly yours

WOW, hey you're all fantastic! uncopyrightable is the word I was thinking of I haven't known that so far until I was told so a few days ago... Have a great day!

Overwhelming answer. And almost all those words come from Latin and some of them from Greek. I like 'dermatoglyphics' , the folds on skin, I never realised I had dermatoglyphics, beautiful word related to fingerprints. (Is 'overwhelming' correctly used here?)

I tried it, I found 38,000+ words with no letter repetition; the longest were.. dermatoglyphics (15), uncopyrightable (15) This was from an indexed dictionary of 'normal / regular' words. Here's the top...

Ok, I will... but I don't think it's possible to find such a word when you don't know it... it'll be damn hard to conclude a word like that I'd say...

It's a bit difficult, and I still haven't had time to find it. Give it a couple of days in case someone else knows it.

Any try?