Urban Dictionary - Urban Dictionary is a Web-based dictionary of slang words and phrases.
ManyThings.org - ManyThings is a multiplatform and user friendly application for students of ESL or EFL to learn the meanings and definitions of different terms and phrases.
Dictionary.com - Dictionary.com is the world’s leading digital dictionary. We provide millions of English definitions, spellings, audio pronunciations, example sentences, and word origins.
DAREDictionary.com - Dictionary of American Regional English presents the meaning of words region wise.
Slang-Dictionary.org - Slang-Dictionary is a web-based database for searching through the database of slang words and learn how different words are getting different meanings in different countries of the world.
Wordspy.com - Finding the meaning of a new word or the word that is not being used on the international level is surely a way of conjuring its existence.