Mega Dictionaries

• yourdictionary.com

Monolingual Dictionaries

• Cambridge Dictionaries Online
• Dictionary.com
• Heinle's Newbury House Dictionary of American English
• Longman Dictionary of Contemporary English Online
• Oxford Dictionary
• TheFreeDictionary.com
• Webster's Dictionary Online

Portuguese

• Lingua Portuguesa Online

Portuguese to English Dictionaries

• LookWAYup
• Ultralingua Online Dictionary
• Webster's Bilingual Online Dictionary

Specialized Dictionaries, Indexes, and Glossaries

• Cardiff Index to Legal Abbreviations
• Dictionary of International Trade and Business
• FindLaw Legal Dictionary
• A Law Dictionary
• Political Economy Terms
• Encyclopedia of Law and Economics

Online Legal Dictionaries

• FindLaw for Legal Professionals
• law.com Law Dictionary