Wiktionary
protein shake
n. A beverage containing protein mixed with milk or water for the purposes of improved nutrition, especially in bodybuilding.
Usage examples of "protein shake".
Looking left, she realized that Elim, the Moal, had been cowering by the engine master the whole time she had been drinking her protein shake.
Emily 7 stood there with a tray that held two cans of protein shake, a glass of water, and a single small pill.