The Cambridge French-English Thesaurus

This highly useful bilingual thesaurus is aimed at all English-speaking learners and users of French at intermediate and more advanced levels. Structured in a uniquely helpful way, it is arranged thematically, with extensive subdivisions into topic categories. Two alphabetical indexes of more than 8,000 words each, one listing English vocabulary and the other French, help readers find what they're looking for easily.
This is the best bilingual thesaurus available
Like the best thesauri, it gives not only analogous words but analogous phrases and expressions as well; moreover it explains in what contexts the different synonyms should be used.
Contains a wealth of information
Let's say you want to look up the French for the word "difficult." You may know that this translates into French as "difficile" but may be curious about other, synonymous words that could be used to mean "difficult" in slightly different contexts. Look up "difficult" in the English-French index at the back of the book, and you're directed to a section that gives you a range of synonymous words and tells you when to use them.
Explains nuances and contexts
In this way it's like a very elaborate dictionary, with phrases as well as words.
Easy to use in French and English
There's not only a long English-French index, but a long French-English one as well, so you can come at it from either language, to find your lists of synonyms in either English or French. Moreover, it gives American English expressions as well as British English ones, wherever they differ.

• A new kind of bilingual thesaurus with translations
• Easy access through alphabetical indexes (one French, one English), and through detailed lists of contents
• Includes a wealth of information about French usage and culture