Vocab Grabber is a new feature from the people who created The Visual Thesaurus.
To quote from an email I received from them:
“…it intelligently extracts key vocabulary from any text you’re interested in, allowing you to sort, filter, and save the most relevant vocab words.”
It’s a bit hard to explain — you probably want to check it out directly.
To be truthful, it’s neat-looking, but I’m not sure it’s particularly useful to students or teachers. But I’m quite happy to be shown that I’m wrong. Let me know if I am…