1. The most wonderful name in the world. It often comes from the name Cecilie, but 'Sille' is a much prettier version of 'Cecilie'!
2. The name is always given to beautiful, lovely girls. If you ever meet a Sille, you are very lucky, and you better keep her!
You can also name pets "Sille"! For example a cute turtle.
Dude: Have you ever met Sille?
Dude2: OH, sure!! She is very pretty, right?
Dude: Yes! then you have met her