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
English-Hindi.net - English to Hindi Dictionary (Free). You can get meaning of any English word very easily. It has auto-suggestion feature which will save you a lot of time getting any meaning. We have a Chrome Extension and an Android App
WordReference - WordReference is a free online Oxford dictionaries for Spanish, French, Italian, German and more.
English to Urdu Dictionary - English to Urdu Dictionary is one of the best language learning application which emphasis on pronunciation of difficult words.
Wiktionary - Open Source wiki-dictionary by the Wikimedia foundation
U-Dictionary - U-Dictionary is one of the sleekest dictionary applications, which helps in removing the language hurdles for its users and is available in 12 different languages.