After quite a few days of work, I'm over with the integration of the online dictionary! (in Tools on the right) I kept the same concepts as for the Translator, that's to say a light widget that can be placed anywhere on the screen. This way it can also be used with any content on the site.

The tool is quite intuitive : select the source language, the word, and that's it. The dictionary will list all the words found. Just under them, a drop-down list will show all the compound phrases available. For example if you search "car", you will be given the choice to select "patrol car" too. The easiest is to try by yourself.

The tool can still be much improved : one click on a kanji to show the kanji info and stroke orders, a button to add a word to your vocabulary lists, the integration of sentences to give examples and therefore put the word into context, etc.