The format with the best commercial dictionary support is MobiPocket. This was once popular, but is now disappearing from ebook readers (because Amazon, who own MobiPocket, want you to buy a Kindle instead). The only MOBI Readers with dictionary support left are the Bookeen Cybook Gen3 (there are also ePub versions, so make sure you get the MOBI) and the more expensive iRex devices.
The other alternative is devices supporting non-commercial dictionaries. The PocketBooks (360, 301, and more coming) allow you to add your own dictionaries and there is already a collection of public domain dictionaries to choose from.
I don't know for sure that any of these do exactly what you want. You might ask in the Forum Français, particularly about the Gen3.
|