When you take a line of cocaine and place it in a black woman's ass crack and start sniffing. The black ass mixed with the white stripe gives it the appearance of a skunk while the blow in the ass gives it an unpleasant aroma.
I was down on 159th street with a dimebag and for $20 this blackhooker let me go skunking.
The act of smoking Marijuana also known as weed while using the toilet especially when referring to smoking weed while shitting. Also known as a "bowl movement"