Wordnik - "Now here's one you don't see every day: Wordnik, which launched out of private beta on Monday and states its mission as "discovering all the words and everything about them." Taking the basic premise of a dictionary, Wordnik supplements each entry with Web 2.0's tastiest treats--relevant Flickr images, Twitter search matches, user-contributed tags and comments--and then invites users to add their own words, too." Caroline McCarthy
http://news.cnet.com/8301-17939_109-10258929-2.html?part=rss&tag=feed&subj=Webware

Wordnik is at www.wordnik.com