I'm sure everyones scores would be a lot lower if we had to describe each word instead of selecting between silly/smart sounding definitions. As was mentioned before, it needs "I don't know" button, otherwise it's too easy to guess.

This approach could also work for getting more accurate results:

1. Show word without any definitions

2. User clicks "I know" or "I don't know"

3. If user clicked "I know", show actual definition of word

4. User selects "I was correct" or "I was not correct"