Rated 5 out of 5 stars

Works find for me. You just cut and paste the word you want to know, put it in the search engine and it takes you to translate.google.com

Rated 3 out of 5 stars

Sounds like a neat add-on.

I couldn't install this add-on. Normally I install .xpi files to Thunderbird but this one is .xml. When I try to install it Thunderbird says it is an invalid package. I tried to local the author for support through the various pages (in Greek?) but I couldn't find an email address or contact link.