A whole collection of various kind of dictionaries and lexicons. Some of them for instance:
- Webster's Revised Unabridged Dictionary
- WordNet English Lexical Database
- FOLDOC Dictionary of Computing
- VERA Acronym Dictionary
- U.S. Gazetteer Places and Zip codes
jDictionary's Lexicon Online Plugin offers you a powerful, easy to use interface for these famous dictionaries.
Please take a look at the short description
for more information and screenshot about Online Lexicon plugin.