The Greyhound is a cocktail made with Vodka and Grapefruit Juice and is perfect for those summer days when you want something refreshing and citrusy. The grapefruit juice gives it a citrusy flavor, while the vodka provides a smooth and clean finish. It is said to have originated in the early 1920s or 1930s in the United States. The Greyhound is a great choice for a poolside drink or a light brunch cocktail. Cheers!