The Longest English Words

Pneumonoultramicroscopicsilicovolcanoconiosis 45 letters
a lung disease.
supercalifragilisticexpialidocious 34 Letters
a word used when you have nothing to say. Not in all dictionaries.
Pseudopseudohypoparathyroidism 30 Letters
An inherited disorder, named for its similarity to pseudohypoparathyroidism in presentation.
Floccinaucinihilipilification 29 Letters
The estimation of something as having no value.
Antidisestablishmentarianism 28 Letters
Any opposition to withdrawing government support of a church or religion.
Incomprehensibilities 21 Letters
(incomprehensible) impossible to understand

These are word lists that we think you may find interesting.