In cooking, jus is a thin sauce made from the juices that run out of meat (or sometimes fish) when it cooks. Cooks may boil those juices a little and add wine or stock, but they do not make it thick like gravy. You will see it on restaurant menus, often in the French phrase au jus, which means the meat is served with its own juices. Though actually, English took the French word as it is, so it still feels a bit fancy and restaurant-like; at home people usually just say meat juice or gravy. It is not a drink, even though the French word jus also means juice in France.