Could there be a way to instead of having the direct english translation, having it define the word in (simple) Dutch? I think this immersion would help improve understanding the language directly as opposed to route memorization, especially at the more advanced level you are targeting.
Honestly I was thinking about that. Or how to best display the new words, so I totally see your point. I might change this in the future, but for this first iteration I just thought: leave the English translation in and see how it works ...