To hit someone when they are not fully expecting it; in order to initiate a fight. Can not be used as a personal verb ("I'm going to jump stupid on her" or "I'm going to jump her stupid").
"I got in a fight with Markie's old girlfriend Penny over the phone yesterday." Breezy said. "I said 'Gurrrrl! If you wanna go you betta jump stupid at school tomorrow!'"