ENCICLOPEDIAS Y DICCIONARIOS

HighBeam™ Encyclopedia
Free encyclopedia. Search or browse over 57,000 articles from the Columbia Encyclopedia.
http://www.encyclopedia.com/

Cambridge Dictionaries Online
http://dictionary.cambridge.org/

Merriam-Webster OnLine
http://www.m-w.com/

The Free Dictionary
English, Medical, Legal, Financial, and Computer Dictionaries, Thesaurus, Acronyms, Idioms,Encyclopedia, a Literature Reference Library, and a Search Engine all in one!
http://www.thefreedictionary.com/

YourDictionary
YourDictionary is a free online English dictionary and much more. The free dictionary search gives you definitions, thesaurus entries, spelling, pronunciation, and etymology results for your word.
http://www.yourdictionary.com/

WordReference.com
WordReference ofrece diccionarios en línea gratis. Para español, contamos con un diccionario monolingüe, de español a inglés, francés, y portugués, y sinónimos/antónimos.
http://www.wordreference.com/es/

Heinle’s Newbury House Dictionary
http://nhd.heinle.com/Home.aspx

The Internet Picture Dictionary
http://www.pdictionary.com/

Urban Dictionary
Urban Dictionary is a slang dictionary with your definitions. Define your world.
http://www.urbandictionary.com/