Pneumoconiosis
Pneumonoultramicroscopicsilicovolcanoconiosis is a lung disease caused by the breathing-in of very small particles of sand or quartz dust found in volcanoes. It was first seen in the Oxford English Dictionary, in 1936. It is "an artificial long word", invented by in 1935 by Everett Smith, president of the National Puzzlers' League (N.P.L.), at its annual meeting.