pregaming
n.— «One common ritual he saw while reporting for the book was “pregaming,” where underage students sat in their dorm rooms or apartments and drank massive amounts of alcohol, usually hard liquor, in order to catch a buzz before going out for the evening.» —“Binge Drinking Entrenched in College Culture” by Jonann Brady ABC News Sept. 7, 2005. (source: Double-Tongued Dictionary)