DICTIONARY AND THESAURUS LINKS

AllWords
Provides definitions, translates words into five different languages, and lets you listen to word pronunciation. 

Cambridge International Dictionaries Online
Allows you to search four different online dictionaries, including the Cambridge International Dictionary of English, the Cambridge Dictionary of American English, Cambridge International Dictionary of Phrasal Verbs, and the Cambridge International Dictionary of Idioms.

Oxford English Dictionary
The online version of the seminal dictionary of the English language. Registration required.

YourDictionary.com
Includes an index of hundreds of online dictionaries in a variety of languages. Subscription required.

Thesaurus.com and Dictionary.com
Related sites with links to writers' resources, games, word information, and more.

Merriam-Webster Online
Features dictionaries and reference products.