Used to describe something, someone or an event which is really annoying or stupid. Has more of a powerful meaning than calling someone a "piece of shit".
I told that "shitpiece" to turn the lights off 5 times now.
Shitpiece I told you to make me some food.
Short for something that is a piece of shit (see also shitbox
"My car is such a shitpiece, it's always talling on me."