A derivative of the term "shart", which is the combination of a fart and diarrhea that occurs simultaneously. To make Shartonnay, you must shart into someone's drink, preferably Chardonnay, thus creating "Shartonnay".
My friend was drinking a glass of Chardonnay and when he went to the bathroom, I sharted in his drink. When he returned, it was Shartonnay.
by shartmaster1 July 03, 2013