What is a nog (as in egg nog)?

What the hell is a nog anyway? Among the festive beverages of Christmas -- including the wassail bowl of warm ale bobbing with apples; the mixture of Scotch and ginger wine known as whisky mac; and the traditional Yuletide punch of rum, brandy, lemons and oranges -- eggnog reigns supreme. So far-reaching is its popularity that, come Thanksgiving, red-and-green cartons of it line the dairy cases of nearly every supermarket across the U.S.

The origins of the word"nog" are shrouded in mystery. It might be a wooden block embedded in a brick wall, into which nails are driven for mounting things. Or it could be a dark foamy ale that's been brewed in Norfolk, England, since the 1600s. But nowadays a nog rarely stands on its own, occurring mainly in compound form as eggnog. Even Webster's definition, with its elastic recipe --"An often alcoholic drink containing beaten egg, milk, or both" -- asks more questions than it answers. And what about"noggin"? It's a waggish term for one's cranium, of course, but the dictionary lists two further meanings: 1) a small quantity of drink, or 2) a small carved mug -- which led one commentator to suggest with apparent seriousness that eggnog actually represents a shortening of the bar-side request,"Egg and grog in a noggin, please." Say it real fast when tipsy, and it turns into"eggnog," I guess.

Some accounts claim that Capt. John Smith knocked back bumpers of eggnog in Jamestown, Va., as early as 1607, and that this"nog" is really just a corruption of the word"grog." In line with 17th century English recipes, Smith's eggnog would have been a simple concoction of ale mixed with eggs, which sounds vile. ...