the hair of the dog

When someone speaks about the hair of the dog, they are referring to a very small measure of drink, usually intended to cure a hangover. This is sometimes referred to as the hair of the dog that bit you, in that in order to cure a hangover, you would drink a very small amount of the same type of alcoholic beverage that caused the hangover in the first place; this originates from the fact that people used to think applying the hair of the dog that bit you to your wound, it would heal.