Wiktionary
a. (context vulgar pejorative colloquial English) (of a person) stupid, or prone to making mistakes interj. (context pejorative Old English): To be characterized as being stupid or with low intellect. n. (context vulgar pejorative colloquial English) A stupid person or someone who makes or has just made a significant mistake.
Usage examples of "dumbshit".
You might have taken command of this battle, and done some dumbshit things, but I am still master of this boat and baron of the whole damn River Battalion, or what's left of it anyway!
The only person who had ever beaten her without cheating was that dumbshit, disrespectful Trooper Macovich.
Macovich was getting increasingly alarmed and pulled up on the collective to clear the trees, a reflex he scarcely noticed anymore because he had to fight for the controls routinely when giving this NASCAR dumbshit a lesson.
It’s hard enough without you always telling me what a dumbshit you think I am.
Do you want to explain this delay to all the dumbshits out there who are counting on getting paid on Friday?
I had to play in phys ed classes and I used to shoot baskets with some dumbshit little kid at one of the foster homes, but that's about it.