Wow! very helpful Addon! and gives a lot of information. I just selected/highlighted a word and I clicked on the extension button/icon on the top toolbar, and a popup window showed up explaining the word i chosen.
Also your website is very well designed and very helpful! 👍
* One suggestion: it would be perfect if when we Right-click our mouse on the selected word, the "context menu" will show up, and we click the icon from there as well.

Easy to add. Simple to use. Comprehensive, and fixes a major pet-peeve of mine, having to stop what I'm doing to Google unfamiliar acronyms.