One of the things that I use a lot that isn't on there is the "Look up" function/service to get the definitions of words from the dictionary, wiki, etc. Super useful and I miss it so much after switching from Safari.
If you hover the cursor over the word and hit command control d, you’ll get the definition in Firefox.
That's helpful. Thanks. Would still like for it to be in the context menu, though, but this will do in a pinch.
Another trick if you have the new "Magic" trackpads: Select the word, place three fingers on the pad, press down (force press), and you can see the definition of the selected word (will be highlighted in yellow).