Acronym Finder: The Acronym Finder is a searchable database of over 4 million acronyms, abbreviations and meanings. Covers: common acronyms, computers, science, technology, government, telecommunications, and military acronyms.
Look up words in the Visuwords online graphical dictionary and thesaurus to find their meanings and associations with other words and concepts. Produce diagrams reminiscent of a neural net. Learn how words associate.
this site collects definitions from different dictionaries so you can easily compare them, includes information about word frequency, sound files for pronunciation, and etymology for most entries. It pulls random examples from literature, and shows current examples from twitter. As the examples are not curated, they are not always examples of best usage to model, but it is also interesting to see how people are really using the word.