11 definitions for lengthy words

This week, I set out to answer a simple question: What are the longest words in the English language?

That led to a not-so-simple question: What do the longest words in the English language mean?

Because many of these words are technical and have little practical use, their definitions do not appear in standard dictionaries. After a little digging, though, I now know what “pseudopseudohypoparathyroidism” means—and so can you.

Below is a list of the longest words in English, along with their definitions. If you can pronounce any of these, treat yourself to a new pair of shoes. If you can work these into a casual conversation, take the rest of the day off.

(Words and definitions from Oxford Dictionaries, Wordnik, Merriam-Webster Medical Dictionary and Wikipedia.)

1. Pneumonoultramicroscopicsilicovolcanoconiosis (45 letters, though this word was created to be the longest word in English and some dictionaries do not recognize it): A lung disease caused by inhaling sand, ash or quartz; also known as silicosis.