So many years ago, while I was a school student, I came to read a very long English word in a Malayalam (the native tongue of the people of Kerala, a state in India) newspaper, the word being PNEUMONOULTRAMICROSCOPICSILICOVOLCANOCONIOSIS.

Believe it or not, I memorized this 45-letter long word with two readings, if my memory serves me right.

The word denotes a lung disease that affects the miners. You can see this word in Chambers Dictionary. This is the longest English word that you can see in a dictionary.

Once a funster said that the longest word in English is none other than SMILES. His argument was that there is a MILE between the two S's. But he did not know the truth that in this respect the longest word should be BELEAGUERED because there is a LEAGUE (three miles) between BE- and -RED