Pneumonoultramicroscopicsilicovolcanoconiosisocazoiopustropusopusoashiososinhalopotropopopobophobia

Pneumonoultramicroscopicsilicovolcanoconiosisocazoiopustropusopusoashiososinhalopotropopopobophobia is the fear of pneumonoultramicroscopicsilicovolcanoconiosis and is the longest word in English dictionaires. (Next longest word being hippopotomonstrosesquippedaliophobia.)