Answers  Good reference for translation and terminology

Cambridge Dictionary (English-English)

Dictionary.com links to language references, games, other languages

Free Dictionary  Multilingual, medical, medical, legal dictionary; includes acronyms, idioms, encyclopedia

Heinle's Newbury House Dictionary --simple, clear definitions

Le grand dictionnaire  good source of French-English terminology (Office québécois de la langue française)

Learner's Dictionary --Merriam-Webster

Lingro  Creates hyper-link to dictionaries for words in a text

LookWAYup multilingual dictionary, thesaurus, translation and other tools

Merriam-Webster (English-English, Spanish-English, thesaurus)

Office Life  Dictionary of Business Jargon (current buzzwords)

Smarter Money  Glossary for English financial terminology

Ultralingua  dictionary, translation and grammar software

Thesaurus  Language resources, thesaurus, articles, translator 

Verbix  online conjugator for an impressive number of languages  Home page

Visual Dictionary images and thematic units

Visu-Words  Online graphical dictionary--links related words graphically

Voycabulary  creates hyperlinks to selected dictionary for words in text

Word Reference Bilingual dictionaries for English, French, Spanish, Italian

Yahoo Spanish-English English-Spanish Dictionary  includes idiomatic usage

Your Dictionary  Resource for many types of dictionaries