To yank down someones pants without their consent, mainly used to embarass the person
I was walking through the halls in school, and out of nowhere, this guys comes behind me and yanks my yoga pants down, exposing my pink Hello Kitty panties with white frilly trimming to everyone in the hall. I was so embarrasses that I had unknowingly began to pee. Seconds later, it completely soaked my embarrassing undies, making the whole situation worse. That was the day I was pantsed at school.