When it's working, it's great. But it keeps breaking - saying sorry no definition found for every single word. It did that a while ago so I turned it off and found a different add-on, but I didn't like it as much and I forgot why I'd stopped using this one so I turned it back on and it worked for about a day. Then it stopped working again. I see an update note saying this problem was fixed, but it has not been fixed.