A traditional unit of volume or quantity, varying with the item contained in the keg. A keg of herring, for example, contains 60 fish. A keg of wine is frequently 12 U.S. gallons (about 45.42 liters), and a keg of beer is 1/2 barrel or 15.5 U.S. gallons (about 58.67 liters). "Keg" comes from an old Norse word for a small barrel