Milk punch is a milk-based brandy or bourbon beverage. It consists of milk, the spirit, sugar, and vanilla extract. It is served cold and usually has nutmeg sprinkled on top. Milk punch may be clarified through the addition of ingredients which cause the milk to curdle, so that the solids contributing to the beverage's opacity may be strained out.
Note that egg nog can be thought of as a variant of milk punch, and was historically referred to as "egg milk punch."