I recently came across lingro.com through my ‘net travels, and while it could be improved in many areas, it’s already one of my favorite tools. While the site has a regular dictionary look-up, what I really love is the overlay feature (or “web viewer” as they call it). You go to lingro.com, select your target language, and enter a website URL; once the page loads, every word on the page is clickable. Click one, and a pop-up window appears with the meaning of the word. There’s also a toolbar at the bottom of the window that you can type a word into, to look up a word that isn’t on the page. (It’s also helpful to look up compound words, as many that are logical in nature don’t have a unique entry.) Here’s what it looks like:
Once you’ve made an account, Lingro keeps track of all of the words you look up. It also maintains a list of all of the sentences that the words appeared in, which makes it all that easier to add sentence items to your SRS application (I recommend Anki).
The site also has a rudimentary flashcard system, but it really is that: rudimentary. I’ve already poked the developers to add an “export” feature.
The dictionaries themselves are all open source, meaning they’re free, and they always will be. Furthermore, they’re largely user-built, so if you hit a word that isn’t in the dictionary you’re using, add it. If you’ve ever used the German dictionary dict.cc, Lingro works more or less the same way. The definitions aren’t always as good as you’d find in a commercial dictionary, but the ease of use – click the word, get a definition – still makes it a worthwhile tool.
Lingro currently has dictionaries for English, Spanish, French, German, Italian, Polish and Swedish.