Used to be great, now simply does not work.

I was looking for an add-on that does what Safari already does, i.e., to highlight a word, right-click, and look up its definition. In Safari, you can get the definition as well as synonyms. The only thing I would love to see is if you click outside the 'dictionary' window pop-up, it goes away. Right now you have to manually close it. Keep improving this. It's really great.

Brilliant!