The act in which one cosumes alchohol prior to attending an event at which alcholic beverages may or may not be served. Often popular with university or college students who can't afford to buy to many drinks at a bar or high school kids who plan to attend events such as dances.
Are you going to Paddy Connolly's tonite? Yea but we are going to pre-drink at Dave's.
Before Johnny went to the dance he pre-drank a mickey at Paul's house.
The drinking that starts before a celebration or an occassion. It usually involves a hardcore group who pride themselves on the amount of alcohol that they can consume.
It could be a few hours early or the day before, usually used as an excuse to women!
Girlfriend: Why have you guys started drinking already? It's 11 in the morning!
Guy: It's the Pre-drink drinks for my birthday, we're just warming up!