Collins English Dictionary - The official Collins English Dictionary online.
Urban Dictionary - Urban Dictionary is a Web-based dictionary of slang words and phrases.
Oxford Dictionaries - Free online dictionary of British English and American English from Oxford.
The Online Slang Dictionary - Learn thousands of real slang words or add your own.
The Free Dictionary - The World's most comprehensive free online dictionary, thesaurus, and encyclopedia with synonyms, definitions, idioms, abbreviations, and medical, financial, legal specialized dictionaries
SlangSite.com - SlangSite.