Good luck. I had the same issue. I can't believe BN doesn't have a good edictionary to sell. I find the Nook dictionary decent. I'm frustrated by not being able to access it freely. This is my DIY solution
https://www.mobileread.com/forums/sho...d.php?t=160363.
I didn't want to pay for an Amazon dictionary that would have a chance of missing some of its functionality after a conversion to epub.
I recently found the 1981 unabridged edition of the Random House dictionary. The hardcover version with over 2,000 pages...Love it. Found it in a thrift shop for $2. I actually had the same dictionary when I was a kid (an earlier edition perhaps) which I got for free. Talk about going back in time. Awesome dictionary.