Dictionaries, Translation and Glossaries

American Slang from the Urban Dictionary, and from Walter Rader. Rader's site features a map of where the slang is used and vulgarity meters. Both sites are user-collaborative.

Aussie Slang
Words and definitions.

Detective slang
Twists, Slugs and Roscoes: A Glossary of Hardboiled Detective Slang.

Etymology dictionary
Where words came from, what they meant centuries ago.

Fiction terms

The Free Dictionary by Farlex. Includes medical, legal, financial, acronym, idiom, Spanish, French, German and Italian dictionaries.

Literary terms

Police Slang How to talk like a cop.

Police Slang and codes
Lingo and number codes for various crimes.

Rhyme Zone Rhyming dictionary and thesaurus.

Teen Slang Youth culture from Fred Lynch.

Thesaurus From Thesaurus.com

Translation by Langenberg: French, German, Portuguese & Italian.

Translation by Paralink: French, German, Portuguese & Russian.

UK: The Queen's Slang
A dictionary of UK colloquialisms.

Visual Dictionary Merriam Webster with pictures.