No one knows for sure exactly when eggnog was first invented, but most food historians believe it descended from a medieval English milky drink called posset.
Some think " nog" comes from the word " noggin, " which was a carved wooden cup that some might use for, say, a nice warm glass of egg drink, hence eggnog.
" What have you been up to lately? " Harry asked Lupin, as Mr, Weasley bustled off to fetch the eggnog, and everybody else stretched and broke into conversation.