grog 
(gr
ŏg)
n.1. An alcoholic liquor, especially rum diluted with water.
2. A rum cocktail, especially when heated and made with lemon or lime juice, sugar, and cinnamon.
[After Old Grog, nickname of Edward Vernon (1684-1757), British admiral who ordered that diluted rum be served to his sailors, from GROGRAM (from his habit of wearing a grogram cloak).]