Campbell R. Harvey's Hypertextual Financial Glossary
This is the largest financial glossary on the internet, and is indexed by letter. Click on the letter of the term you want and scroll down the list until you find it. Terms are hyperlinked throughout the index, so if you don't know a term, click on it and you will be taken to that term. The glossary assumes a basic (sometimes more in-depth) knowledge of financial terms, but the hypertexts will help fill in any gaps.
Campbell R Harvey
Instruction: Teaching Tools
Teacher / Faculty, Student / Learner, Parent / Informal Education