idea

[noun] Spiel (german) = Game (english)
[verb] spielen (german) = to play (english)

This is quite and obvious one that hasn't been posted, but problem the most used out of all of them.

It can be deciphered as such: Definition of English word spiel in my own words without looking at dictionary = 1. convincing argument, 2. utterly ridiculous argument, 3. play on words, 4. joke, 5. demonstration, 6. delivery of a presentation, 7. detailed verbal analysis, 8. collaborative leg pulling device used on 1 or more people