OJ is a short, everyday way to say orange juice. You see it on breakfast menus, on cartons in the shop, and in speech when people do not bother with the two full words: Want some OJ? It is informal, but shops and cafes print it as if it were a normal name for the drink. Though actually, in this food-and-drink world it only means orange juice — not apple juice, not lemon juice. The same two letters can stand for other things in other places, so the letters alone do not tell you; the glass, the fridge, or the menu does. People say a glass of OJ or a carton of OJ.

柳橙汁（台灣；菜單上也常直接寫 OJ。中國大陸較常說橙汁）