| Acronym Database | Peter Flynn. Over 15,000 acronyms defined. |
| Acronym Finder | Mountain Data Systems. Over 238,000 acronyms/abbreviations defined. |
| Chambers 21st Centruy Dictionary/Chambers Thesaurus/Chambers Biographical Dictionary | |
| Merriam-Webster Dictionary and Thesaurus | |
| OneLook Dictionary Search | Define, find, or translate words - five million words in 900 dictionaries in database. |
OneLook Reverse Dictionary
| Describe a concept and get a list of words and phrases related to that concept |
| Oxford Reference Online | Over 100 dictionary, language reference, and subject reference works |
| Webster's Third New International Unabridged Dictionary and Thesaurus | |