coffee substitute
Any replacement for coffee. Energy drinks are commonly used as a coffee substitute. Tea can be a coffee substitute for some people, as well as caffeine tablets.
Person #1: "Do you still drink coffee?"
Person #2: "Come to think of it, not as much. I am using energy drinks much more often as a coffee substitute."
Person #2: "Come to think of it, not as much. I am using energy drinks much more often as a coffee substitute."