1. Pneumonoultramicroscopicsilicovolcanoconiosis (45 letters)
An invented long word said to mean a lung disease caused by inhaling very fine ash and sand dust.
2. Hippopotomonstrosesquippedaliophobia (36 letters)
fear of long words.
This word has four basic components changed to fit together phonologically: hippopotamus, monstrous, sesquipedalian, and phobia.
3. Supercalifragilisticexpialidocious (34 letters)
extraordinarily good; wonderful.
4. Pseudopseudohypoparathyroidism (30 letters)
A relatively mild form of pseudohypoparathyroidism that is characterized by normal levels of calcium and phosphorus in the blood.
5. Floccinaucinihilipilification (29 letters)
The estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).
6. Antidisestablishmentarianism (28 letters)
Opposition to the disestablishment of the Church of England.
7. Honorificabilitudinitatibus (27 letters)
Deserving of honor, capable of receiving the honor.
8. Thyroparathyroidectomized (25 letters)
Surgical removal of the thyroid and parathyroid glands.
9. Dichlorodifluoromethane (23 letters)
A colourless nonflammable gas easily liquefied by pressure.
10. Incomprehensibilities (21 letters)
The state of being impossible or extremely difficult to understand.
