The mood someone is in when they have lingering diarrhea, which results in an irritation due to over wiping.
Charles will not be able to attend his yoga class today because he is rather butt grumpy.
Ex. 1) Bro, can we pull into that gas station for a minute? I got really bad silly butt.
Ex. 2) Take it easy with that ice cream, Louise, lest you want silly butt.
A man or woman's butt that has become so flat from multiple hours of sitting at a computer, it assumes the shape of a pancake.
"Damn son look at that nerd butt, what do they do to get that?"
"They work in IT"
Verb
1. The act of defecation
2. The need to defecate
Oh man, I'm making butt potatoes tonight
Losing your anal virginity
I lost my butt potato last night.