A piece of skin, generated by a very fat body, which became very skinny, so only the skin remaines. It is also very sweaty, eg dutch "zweterig", thats why it starts with zw.
The "oepert" part of the word is a abbreviation of the dutch word "poepert", which refers to the anus and buttocks area.
With this Zwoepert, one can swaffel objects.
Cecilia has a huge zwoepert. She always swaffelt everyone and everything with it.
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.