• Urban Dictionary: collaborative slang dictionary
• Peevish: English slang dictionary
• LondonSlang: London slang dictionary
• IrishSlang: Irish English slang dictionary
• Koalanet: Australian slang dictionary
• NewZealandSlang: New Zeeland slang dictionary
• French slang: colloquial Canadian French, with translation into English
• Dictionary of slang and colloquial English by John Farmer & William Henley (1905)
• Slang and its analogues, past and present, A dictionary historical and comparative of the heterodox speech of all classes of society for more than three hundred years, by John Farmer & William Henley (1890)
A-B - C-Fi - Fl-H - I-M - N-Ra - Re-St - St-Z
• The slang dictionary, etymological, historical and anecdotal, by John Camden Hotten (1913)
• Passing English of the Victorian era, a dictionary of heterodox English, slang and phrase, by James Redding Ware (1909)
• Londinismen, slang und cant: London slang, English-German dictionary, by Heinrich Baumann (1887)
• A classical dictionary of the vulgar tongue by Francis Grose (1785)
• Lexicon balatronicum, a dictionary of buckish slang, university wit, and pickpocket eloquence (1811) + online dictionary
• Grose's classical dictionary of the vulgar tongue, revised by Pierce Egan (1823)
• A new dictionary of the terms ancient and modern of the canting crew, in its several tribes, of Gypsies, beggers, thieves, cheats, &c., with an addition of some proverbs, phrases, figurative speeches, &c., by B. E. Gent (1699)
It's the first English dictionary of slang.
• Dictionary of American slang by Barbara Kipfer & Robert Chapman (2008) 
• American slang dictionary: the ultimate reference to nonstandard usage, colloquialisms, popular jargon and vulgarisms, by Richard Spears (2006)
• The Oxford dictionary of American political slang (2006)
• Dictionary of American Slang by Harold Wentworth & Stuart Flexner (1975)
• The American slang dictionary by James Maitland (1891)
• Glossary of French slang by Olivier Leroy (1922)
• A careful selection of modern Parisian slang, including the new "argot des tranchées", with explanatory notes, by Charles Marchand (1916)
• Argot and slang, French and English dictionary of the cant words, quaint expressions, slang terms and flash phrases used in the high and low life of old and new Paris, by Albert Barrère (1889)
• Graphie, phonie et encodage dialectal: the Cockney dialect in Somerset Maugham's Liza of Lambeth, by Manuel Jobert, in Lexis (2009)
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