Definition (点餐)
When ordering food at a restaurant, this phrase indicates that you would like the food packaged to take away rather than consuming it at the premises.
外带（食物）
I'd like a cheeseburger and a strawberry milkshake to go.
我想要一个芝士汉堡和草莓奶昔外带。
Could I get two chocolate brownies to go, please?
请给我两个巧克力布朗尼外带。
Can we get an extra order of fries to go?
我们可以多点一份薯条外带吗？