pneumonoultramicroscopicsilicovolcanoconiosis

A lung disease caused by inhaling ash, small sand, and other small dust.

Child : Mother, I learned a new word at school today!
Mother : Really? What is it?
Child : pneumonoultramicroscopicsilicovolcanoconiosis
Mother : *Shrieks in fear**starts hyperventilating*
Child: Whats wrong? do you have hippopotomonstrosesquippedaliophobia?
Mother : Ahh! make it stop! Were all gonna Dieee!*Faints in fear*
Child: mom?