Unless you are looking for specifically websites you could try this book-
Shakespeare A-Z by George Usher
Published by bloomsburyreference
ISBN number 0-7475-6999-1
www.bloomsbury.com/reference
If you take this info to your local bookstore they will be able to help you find it. It has the Shakespearean words and explanations of them. It says on the back " Ideal for students of English literature and Theatre Studies at GCSE and A level". Its alphabetical and reads just like a dictionary!