A sesquipedalian is a person who overuses uncommon words like lameen (a bishop’s letter expressing a fault or reprimand) or salvestate (to transport car seats to the dining room) just for the sake of it. The first of those italicized words is real. The second two aren’t. But they totally should be. They’re the invention of a new website called This Word Does Not Exist. Powered by machine learning, it conjures up entirely new words never before seen or used, and even generates a halfway convincing definition for them. It’s all kinds of brilliant.

“In February, I quit my job as an engineering director at Instagram after spending seven intense years building their ranking algorithms like non-chronological feed,” Thomas Dimson, creator of This Word Does Not Exist, told Digital Trends. “A friend and I were trying to brainstorm names for a company we could start together in the A.I. space. After [coming up with] some lame ones, I decided it was more appropriate to let A.I. name a company about A.I.”

Then, as Dimson tells it, a global pandemic happened, and he found himself at home with lots of time on his hands to play around with his name-making algorithm. “Eventually I stumbled upon the Mac dictionary as a potential training set and [started] generating arbitrary words instead of just company names,” he said.

If you’ve ever joked that someone who uses complex words in their daily lives must have swallowed a dictionary, that’s pretty much exactly what This Word Does Not Exist has done. The algorithm was trained from a dictionary file Dimson structured according to different parts of speech, definition, and example usage. The model refines OpenAI’s controversial GPT-2 text generator, the much-hyped algorithm once called too dangerous to release to the public. Dimson’s twist on it assigns probabilities to potential words based on which letters are likely to follow one another until the “word” looks like a reasonably convincing dictionary entry. As a final step, it checks that the generated word isn’t a real one by looking it up in the original training set.

This Word Does Not Exist is just the latest in a series of “[Insert object] Does Not Exist” creations. Others range from non-existent Airbnb listings to fake people to computer-generated memes which nonetheless capture the oddball humor of real ones.

“People have a nervous curiosity toward what makes us human,” Dimson said. “By looking at these machine-produced demos, we are better able to understand ourselves. I’m reminded of the fascination with Deep Blue beating Kasparov in 1996 or AlphaGo beating Lee Sedol in 2016.”