Spiked is used to describe when an alcoholicbeverage is mixed in with another, non-alcoholic drink (most common is Gatorade). The maximum content in the mixture is the non-alcoholic beverage. the beverage can also be tainted with drugs (GHB).
An expression that is used when someone is at a party and they add an alcoholic beverage to the punch bowl so everyone at the party gets tipsy or drunk.