French Slang

The Alternative French Dictionary - Slang, profanities, insults and vulgarisms from all the world. The Alternative dictionaries are a collection of various forms of "bad language" from many languages. At the moment, there are 2743 entries in 162 dictionaries. This is a collaborative project with contributions from a lot of people. The pages are developed and edited by Hans-Christian Holm.
CoolSlang: French Slang with English Translation - User-generated slang dictionary in many languages.
Dictionnaire Argot Francais - Monolingual searchable French dictionary of slang, with over 18,000 slang words and expressions.
Glosssaire Quebecois - Monolingual French Canadian dictionary.
Le Jargon Francais - Monolingual French dictionary of slang, from linux-france.org.
Language Realm: French Dictionary of Proverbs (Kotowaza) - Listing of colloquial French proverbs and phrase.
Language Realm French Slang Dictionary - This dictionary is a comprehensive and in-depth look at all the slang, vulgarisms, curses, and insults, plus a lot more, available in French. Searchable by French terms; most useful for looking up slang words and vernacular that eludes understanding.
Wikibooks: French/Appendices/Slang - From Wikibooks, the open-content textbooks collection.