Welcome to Thunderbird Add-ons.
Add extra features and styles to make Thunderbird your own.Close
Imperfect, but great Rated 4 out of 5 stars
The perfect solution of course being a native (or seemingly so) integration where cmd+ctrl+d brings up the little definition popup, but this one is good enough for me (for now).
One request - Is it possible to make it so the 'Look Up in Dictionary' menu item is available even without highlighting the word? I've seen this implemented in other plugins, it'll be great if I don't have to painstakingly highlight the exact word every time I want to look something up.