Too long.... Dangerous too.......

Pneumonoultramicroscopicsilicovolcanoconiosis

The longest known (approved) techincal word in english.Pneumonoultramicroscopicsilicovolcanoconiosis

 a factitious word alleged to mean 'a lung disease caused by the inhalation of very fine silica dust, causing inflammation in the lungs.'

This word was invented in 1935 by Everett M. Smith, president of the National Puzzlers' League, at its annual meeting. The word figured in the headline for an article published by the New York Herald Tribune on February 23, 1935, titled "Puzzlers Open 103d Session Here by Recognizing 45-Letter Word":

"  Pneumonoultramicroscopicsilicovolcanoconiosis succeeded electrophotomicrographically as the longest word in the English language recognized by the National Puzzlers' League at the opening session of the organization's 103rd semi-annual meeting held yesterday at the Hotel New Yorker. The puzzlers explained that the forty-five-letter word is the name of a special form of silicosis caused by ultra-microscopic particles of silica volcanic dust..."