n. When minors engage in illegal but fun activities to make up for the fact that they're stuck in high school at the whim of the state government until they turn 18.
Often a symptom of senioritis, and usually accompanied by the fear that the kid who's parents are away will magically return to discover upwards of 20 shitfaced teens in varying states of undress in the living room.
newspaper reporter: "under age drinking is on the rise... beware"
kid #1: under age drinking is a joke, I don't even get hangovers anymore!
kid #2: you're so right, man. Look I stole my parents' vodka, let's party!