Dictionaries

• Acronyms, Abbreviation or Initialism
• Aisa: Multilingual Dictionary
• Answer.com - Encyclopedia (enter a word o phrase) 
• Cambrigde Dictionary Online
• Fotoidiomas(Visual Dictionary)
• Howjsay (Talking Dictionary of English Pronunciation)
• iLearnWords 
• Linguee.es (Dictionary and Browser of Translations)
• Leoloqueveo (Visual/Thematic Dictionary)
• MacMillan Monolingual Dictionary
• Shahi (A visual monolingual dictionary - Flickr, Google and Yahoo! images)
• Thesaurus (Synonyms - Antonyms)
• Trilingual Index of Expressions
• Visual Multilingual Dictionary
• Wikipedia (The Free Encyclopedia)
• Wordreference
• Macmillan Monolingual Dictionary and Thesaurus