/grog/ , n.
1. a mixture of rum and water, often flavored with lemon, sugar, and spices and sometimes served hot.
2. any strong alcoholic drink.
3. fired and crushed clay.
[ 1760-70; from Old Grog (alluding to his GROGRAM cloak), the nickname of Edward Vernon (d. 1757), British admiral, who in 1740 ordered the alcoholic mixture to be served, instead of pure spirits, to sailors. ]