Usually compromised of a mixture of fruits, yogurts, and ice; and prepared in a blender to make a cold delicious drink.
However, if you are older and pursue something a little stronger. You can add or substitute beer into the formula, however many times until you find the drink that fits you.
John: What are you drinking over there?
Sally: Oh! Just a smoothie!
John: That drink that's usually made of ice, yogurt, and fruit in a blender?
Sally: Sort of. It's actually beer, beer, and more beer in a funnel
John: is that still a ssmoothie though?