The longest word in english and medicine!!!

[Yaxya]

pneumonoultramicroscopicsilicovolcanoconiosis:'a lung disease caused by the inhalation of very fine silica dust found in volcanoes' .
pneumon/o = lungs
ultra = extreme degree
microscipic = too small to be seen
silic/o = silica
volcano = volcano
coni = dust
osis = condition

[Doctoor]

Hey Yaxya..
There are other words which are longer than this..
The longest word which I can't write it here because it contains 189,819 letters, you can find it here: http://en.wikipedia.org/wiki/Longest_word_in_English
This is a Joke about words, enjoy it:
An Ukrainian immigrant in USA went to the Motor Vehicles Registry (Department of Motor Vehicles or Secretary of State in some states) to apply for a driver's license. He had to take an eye test.The clerk shows him a card with the letters:

C Z W I X N O S T A C Z

"Can you read this?" the clerk asks.

"Read it?" the Ukrainian replies, "I know this guy."
Question for our members in Ukraine: does such a name exist?

[Yaxya]

thanks doctor for the information and for the joke as well....the word i mention is the longest word in a major dictionary like Oxford dictionary others they are names of chemicals,places and transliteration from other languages so they are not present in the major dictionaries...