The longest word in the English language dictionaries is pneumonoultramicroscopicsilicovolcanoconiosis. This is a word that refers to a lung disease contracted from the inhalation of very small silica particles, mostly from a volcano; it is technically the same as silicosis.
It's pronounced (new-mono-ull-tra-micro-scopic-silico-volcano-con-i-o-sis)
