Thanks for the feedback!
I can see how this would be useful in your case, but I’m wary of adding extra complication to the Explain prompt for this now. Might reconsider in future.
One idea which is probably less than ideal but which you can try right now is the new Ask AI feature: Ask AI: custom ChatGPT prompt feature for premium users (experimental).
You could try prompts like: “Is this a French word?” or even “Is this a French word which would be useful to learn for a learner at B2 level?” to see if they are helpful.