Found this on Reddit, it was pretty neat. Basically say yes or no to knowing a word. The catch is there's fake words in there which kill your score if you say yes to them.

http://vocabulary.ugent.be/


I managed a 68%, with a single yes said to a word that doesn't exist. I had to seriously think hard for some of them. My fastest answer to say yes to was "vodka" in .5 seconds