pneumonoultramicroscopicsilicovolcanoconiosis

An invented long word said to mean a lung disease caused by inhaling very fine ash and sand dust, coming from 1930s: a word invented (probably by Everett M. Smith, president of the National Puzzlers' League) in imitation of very long medical terms.

Friend: Hey man, the doctor said that I have pneumonoultramicroscopicsilicovolcanoconiosis. I might die.
Me: What?
Friend: I said that I have pneumonoultramicroscopicsilicovolcanoconiosis.
Me:wHAt?