This is where mixology meets etymology.

Nobody is quite sure where the name comes from. But the drink has its roots in many forms of milk-and-alcohol libations that were common in Europe since at least the Middle Ages. One such drink was “Posset,” a glass of milk curdled with alcohol, which was believed to have medicinal properties; it was almost synonymous with winter, the cold and flu season. In Spain, the alcohol of choice was Madeira, which was widely available, and they added some spices to improve the flavor.

Sometime later in England, the recipe was given a bit of a flip. By taking the drink and flipping it back and forth between two pitchers, you get a little froth into the mix. Add an egg into the equation, and you get a thicker, even frothier concoction known as an “Egg Flip.” And, since the vessel it was most commonly served in was a wooden cup known as a “Noggin,” the name morphed into “Egg Nog.”

Maybe. Others believe “Egg Nog” is an American invention. Here, in the English colonies, folks originally enjoyed their holiday dairy beverage spiked with brandy or sherry. But as taxes on these wines became onerous, the colonists started substituting cheap rum that came up from the Caribbean via the slave trade. Since the resulting drink was defined by eggs and grog, it became “Egg-n-Grog,” which was later shortened to “Egg Nog.”

Today, folks in America continue to use potent spirits like rum and bourbon, while the Europeans usually still opt for wine. But as long as the recipe contains dairy, alcohol, egg and spices, it’s an Egg Nog.

And whether you are studying its history or indulging in its chemistry, one thing is for sure.

It will go to your noggin.