Made from eggs, sugar, cream, and rum, eggnog is a traditional Christmas drink, first referred to in the early nineteenth century. Originally, however, the refreshment was made with ale instead of rum, as suggested by the nog part of its name, nog being an archaic English word meaning strong ale (eggnog is sometimes still made with ale in Germany where it is called bieresuppe, meaning beer-soup). The word nog was first recorded in English in the late seventeenth century, but little else is known about its origin. Likely it is somehow related to noggin, a seventeenth century name for a small drinking cup, one that held only a quarter of a pint; in turn, this noggin is likely the same one that means head, as in, “He bumped his noggin,” the connection being that the head is a kind of “cup” for the brain (the word head, in fact, derives from an Indo-European source that meant cup or bowl).
A beverage composed of milk or cream, raw eggs, assorted spices, and frequently incorporating alcoholic liquors such as brandy, rum, or whiskey.