Dictionaries

French-French Dictionaries:

• Le Trésor de la Langue Française Informatisé
  Definitions, expressions, etymologies, and other historical linguistic info
  http://atilf.atilf.fr/tlf.htm

Multilingual Dictionaries:

• WordReference Dictionaries
Definitions, expressions, conjugations, discussion forums
http://www.wordreference.com/
• TV5 Multi-function Dictionary
Definitions (Fr-Fr, Fr-Eng, Eng-Fr), synonyms, conjugations
http://dictionnaire.tv5.org/