Do you know what pneumonoultramicroscopicsilicovolcanoconiosis means? Well, this guy does!
Michael Bryan, 16, used the word at a Youth Select Committee meeting in July, when talking about money spent on mental health.
According to the Oxford English Dictionary, pneumonoultramicroscopicsilicovolcanoconiosis is "an invented long word said to mean a lung disease caused by inhaling very fine ash and sand dust".
Want to use a fancy word like this to impress your friends and family? Newsround has got you covered...
Means: Loving of long words
Sentence to use it in: As someone who is quite sesquipedalian, I make it my mission to use loads of long words in all my conversations.
Means: Someone with a fear of long words
Sentence to use it in: Any hippopotomonstrosesquipedaliophobics are going to really hate me with my new vocabulary.
Means: It is the name of a Welsh village and is the longest place name in the UK!
Sentence to use it in: Fancy a trip to Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch this summer?
Means: The act of deciding that something is worthless. This is one of the longest words in the English language, so any sesquipedalian would be wise to know this one.
Sentence to use it in: I am very offended by my friend's floccinaucinihilipilification of my amazing new vocabulary.
Means: If you do something facetiously, you are deliberately treating something that is perhaps quite serious with inappropriate jokes or humour. It's a great word because it has every single vowel - and the semi-vowel 'y' - just once!
Sentence to use it in: You should never behave facetiously when it comes to important and serious matters such as the use of fancy words.
Means: This originally meant when people were against the removal of the Church of England's status, but now it can be used to refer to a movement against the government taking away their support for a particular church or religion.
Sentence to use it in: Did you know that antidisestablishmentarianism was left out of the 10th edition of the Concise Oxford Dictionary by mistake? No, but you do now.
Means: The perfect example of something
Sentence to use it in: I am a quintessential sesquipedalian.
Means: Work that you do just so that you look busy, but it isn't actually useful.
Pronounced: As it looks - this one's not too tricky to pronounce!
Sentence to use it in: You might think my mission to learn more long words is a complete boondoggle, but it's actually extremely interesting.
Means: The use of lots of words where fewer words would actually do the job.
Sentence to use it in: My love of circumlocution means you may think my sentences are unnecessarily long - but I would disagree.
Means: To extravagantly boast
Sentence to use it in: I don't like to gasconade, but my vocabulary after reading this article is quite exceptional.
Means: Huge or gigantic. It has a capital letter as the word comes from the name of a land in Gulliver's Travels where everything is enormous.
Sentence to use it in: I have a vocabulary of Brobdingnagian proportions!
Means: All this word means is brick-red in colour... But it's a much funnier way of saying it!
Sentence to use it in: I am a huge fan of your lateritious T-shirt.
Means: To confuse (someone)
Sentence to use it in: Do you want to learn some more long words too or are you too discombobulated after reading this article?