I just stumbled across a lovely set of links from Yahoo!
Financial Reference>Glossaries
I love how Yahoo aggregatessouces, and this is very useful when trying to figure out what those annual reports, proxies, 8-Ks and other business financial documents really mean.
I have always been especially fond of Moneywords, which disappeared a while back, but I have become very fond of the Investopedia
Investopedia (which doesn’t appear to be a Wiki, despite its name), has an excellent financial dictionary, as well as tutorials and a variety of research tools.
Enjoy!