Purple drank
From the archives of TiPWiki, the unofficial Duke TIP Wiki
Purple Drank was a non-alchoholic drink first mixed at Davidson Term One. This was a drink highly craved by any who tasted it. It was envied for its sweet taste and lovely purple color. It was even said to arouse the senses when enough was ingested. There were only four people who knew the exact recipe and Tipsters were often seen begging for a glass. To this day they are said to be the only ones to know the true recipe.
Also refers to the Grape Crush spiked with liquor that Maddie took giant gulps from during dinner, not knowing it was spiked.