BTW, I've thought of an awesome makeshift solution and if someone can make this happen, you can take credit for it.
How about having an epub 'book' of words...just a list of words in alphabetical order. How many entries are in a standard college dictionary nowadays? 250K? When you need a definition of a word, you simply open up this book, find the word and then use the Nook dictionary to do the work like you would if you were reading a regular book.