@lordeagle,
There's also a hidden beta feature you can try, called MyWords. You can enable it by adding
Code:
[FeatureSettings]
MyWords=true
to the Kobo config file. Possibly needs a reboot afterwards.
If the config already contains a [FeatureSettings] section you only need to add the second line.
ETA: When you look-up a word the dictionary popup has an extra button top-right 'Add to My Words', Then you can look at the words you've stored via
More > Activity > My Words tab
These words are stored in your KoboReader.sqlite database in the WordList table